You download the mod tool from here:
WWW LinkThen when you've finished downloading, unzip the folder. In the folder is another folder named 'Reference Data'. Open the Reference Data folder and five folders named 'GameInfo', 'Mesh', 'Particle', 'String', and 'Window' should be inside. If you want to modify entity files, open the GameInfo folder, choose a file, and open it with the Wordpad. The file should look like this:
TXT
entityType "CapitalShip"
ability:0 "AbilityGaussBlast"
ability:1 "AbilityFlakBurst"
ability:2 "AbilityAdaptiveShield"
ability:3 "AbilityLastStand"
defaultAutoAttackRange "GravityWell"
defaultAutoAttackOn TRUE
prefersToFocusFire TRUE
autoJoinFleetDefault TRUE
canBomb TRUE
hasBombingLevels FALSE
baseDamage 43.000000
basePopulationKilled 1.700000
bombingFreqTime 10.000000
baseRange 3000.000000
bombTransitTime 12.000000
bombEffectCount 3
bombEffectAngleVariance 15.000000
bombEffectsDef
weaponType "Projectile"
burstCount 1
burstDelay 0.000000
muzzleEffectName "Weapon_TechCapitalPlanetBombing_Muzzle"
muzzleSoundMinRespawnTime 0.100000
muzzleSounds
soundCount 1
sound "WEAPON_TECH_PLANETBOMB_MUZZLE"
hitEffectName "Weapon_TechCapitalPlanetBombing_Hit"
hitHullEffectSounds
soundCount 3
sound "EXPLOSION_SUB4"
sound "EXPLOSION_SUB4_ALT1"
sound "EXPLOSION_SUB4_ALT2"
hitShieldsEffectSounds
soundCount 3
sound "EXPLOSION_SUB4"
sound "EXPLOSION_SUB4_ALT1"
sound "EXPLOSION_SUB4_ALT2"
projectileTravelEffectName "Weapon_TechCapitalPlanetBombing_Travel"
mainViewIcon "MAINVIEWICON_CAPITALSHIP_TECHBATTLESHIP"
basePrice
credits 3000.000000
metal 400.000000
crystal 250.000000
slotCount 50.000000
BuildTime 75.000000
MaxHullPoints
StartValue 3000.000000
ValueIncreasePerLevel 120.000000
MaxShieldPoints
StartValue 1250.000000
ValueIncreasePerLevel 135.000000
HullPointRestoreRate
StartValue 1.500000
ValueIncreasePerLevel 0.100000
ShieldPointRestoreRate
StartValue 3.000000
ValueIncreasePerLevel 0.200000
ArmorPointsFromExperience
StartValue 5.000000
ValueIncreasePerLevel 0.450000
maxMitigation
StartValue 0.65
ValueIncreasePerLevel 0.01111
MaxAntiMatter
StartValue 225.000000
ValueIncreasePerLevel 20.000000
AntiMatterRestoreRate
StartValue 0.750000
ValueIncreasePerLevel 0.080000
CultureProtectRate
StartValue 0.300000
ValueIncreasePerLevel 0.050000
NameStringID "IDS_CAPITALSHIP_TECHBATTLESHIP_NAME"
DescriptionStringID "IDS_CAPITALSHIP_TECHBATTLESHIP_DESCRIPTION"
picture "CAPITALSHIPPICTURE_TECHBATTLESHIP"
Prerequisites
NumResearchPrerequisites 0
roleType "Invalid"
statCountType "CapitalShipBattleship"
numRandomDebrisLarge 6
numRandomDebrisSmall 12
numSpecificDebris 0
armorType "CapitalShip"
hudIcon "HUDICON_CAPITALSHIP_TECHBATTLESHIP"
smallHudIcon "HUDICONSMALL_CAPITALSHIP_TECHBATTLESHIP"
infoCardIcon "INFOCARDICON_CAPITALSHIP_TECHBATTLESHIP"
minZoomDistanceMult 1.250000
NumWeapons 3
Weapon
WeaponType "Beam"
damageEnums
AttackType "CAPITALSHIP"
DamageAffectType "AFFECTS_SHIELDS_AND_HULL"
DamageApplyType "OVERTIME"
DamageType "ENERGY"
WeaponClassType "BEAM"
DamagePerBank:FRONT 126.000000
DamagePerBank:BACK 0.000000
DamagePerBank:LEFT 0.000000
DamagePerBank:RIGHT 0.000000
Range 5000.000000
PreBuffCooldownTime 14.000000
CanFireAtFighter FALSE
SynchronizedTargeting TRUE
PointStaggerDelay 0.250000
TravelSpeed 0.000000
Duration 4.000000
WeaponEffects
weaponType "Beam"
burstCount 1
burstDelay 0.000000
muzzleEffectName "Weapon_TechCapitalBeamHeavy_Muzzle"
muzzleSoundMinRespawnTime 0.100000
muzzleSounds
soundCount 1
sound ""
hitEffectName "Weapon_TechCapitalBeamHeavy_Hit"
hitHullEffectSounds
soundCount 1
sound ""
hitShieldsEffectSounds
soundCount 1
sound ""
beamEffectSounds
soundCount 1
sound "WEAPON_TECHCAPITALBEAMHEAVY_TRAVEL"
beamGlowTextureName "TechCapitalBeam_Glow"
beamCoreTextureName "TechCapitalBeam_Core"
beamWidth 35.000000
beamGlowColor ffffffff
beamCoreColor ffffffff
beamTilingRate 3.000000
Weapon
WeaponType "Projectile"
damageEnums
AttackType "CAPITALSHIP"
DamageAffectType "AFFECTS_SHIELDS_AND_HULL"
DamageApplyType "BACKLOADED"
DamageType "PHYSICAL"
WeaponClassType "AUTOCANNON"
DamagePerBank:FRONT 27.000000
DamagePerBank:BACK 49.500000
DamagePerBank:LEFT 49.500000
DamagePerBank:RIGHT 27.000000
Range 5000.000000
PreBuffCooldownTime 4.500000
CanFireAtFighter FALSE
SynchronizedTargeting FALSE
PointStaggerDelay 1.000000
TravelSpeed 4000.000000
Duration 0.000000
WeaponEffects
weaponType "Projectile"
burstCount 15
burstDelay 0.060000
muzzleEffectName "Weapon_TechCapitalAutoCannonHeavy_Muzzle"
muzzleSoundMinRespawnTime 0.770000
muzzleSounds
soundCount 3
sound "WEAPON_TECHCAPITALAUTOCANNONHEAVY_MUZZLE"
sound "WEAPON_TECHCAPITALAUTOCANNONHEAVY_MUZZLE_ALT1"
sound "WEAPON_TECHCAPITALAUTOCANNONHEAVY_MUZZLE_ALT2"
hitEffectName "Weapon_TechCapitalAutoCannonHeavy_Hit"
hitHullEffectSounds
soundCount 1
sound "WEAPONIMPACT_PHYSICALHEAVY_HITHULL"
hitShieldsEffectSounds
soundCount 1
sound "WEAPONIMPACT_GENERICHEAVY_HITSHIELDS"
projectileTravelEffectName "Weapon_TechCapitalAutoCannonHeavy_Travel"
Weapon
WeaponType "Projectile"
damageEnums
AttackType "CAPITALSHIP"
DamageAffectType "AFFECTS_SHIELDS_AND_HULL"
DamageApplyType "BACKLOADED"
DamageType "ENERGY"
WeaponClassType "LASERTECH"
DamagePerBank:FRONT 45.375000
DamagePerBank:BACK 0.000000
DamagePerBank:LEFT 0.000000
DamagePerBank:RIGHT 0.000000
Range 5000.000000
PreBuffCooldownTime 5.500000
CanFireAtFighter FALSE
SynchronizedTargeting TRUE
PointStaggerDelay 0.900000
TravelSpeed 2000.000000
Duration 0.000000
WeaponEffects
weaponType "Projectile"
burstCount 1
burstDelay 0.000000
muzzleEffectName "Weapon_TechCapitalLaserHeavy_Muzzle"
muzzleSoundMinRespawnTime 0.100000
muzzleSounds
soundCount 2
sound "WEAPON_TECHCAPITALFIREBALLHEAVY_MUZZLE"
sound "WEAPON_TECHCAPITALFIREBALLHEAVY_MUZZLE_ALT1"
hitEffectName "Weapon_TechCapitalLaserHeavy_Hit"
hitHullEffectSounds
soundCount 1
sound "WEAPONIMPACT_PHYSICALHEAVY_HITHULL"
hitShieldsEffectSounds
soundCount 1
sound "WEAPONIMPACT_GENERICHEAVY_HITSHIELDS"
projectileTravelEffectName "Weapon_TechCapitalLaserHeavy_Travel"
m_weaponIndexForRange 0
mass 10000.000000
ShieldMeshName "Shield_TechBattleship"
maxAccelerationLinear 100.000000
maxAccelerationStrafe 10.000000
maxDecelerationLinear 500.000000
maxAccelerationAngular 1.000000
maxDecelerationAngular 9.999996
maxSpeedLinear 525.000000
squadTypeEntityDef:0 "SquadTechCombat"
squadAntiMatterCost:0 0.000000
squadTypeEntityDef:1 "SquadTechBomber"
squadAntiMatterCost:1 0.000000
NumSoundsFor:ONATTACKORDERISSUED 4
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONATTACKORDERISSUED_0"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONATTACKORDERISSUED_1"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONATTACKORDERISSUED_2"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONATTACKORDERISSUED_3"
NumSoundsFor:ONCREATION 1
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONCREATION"
NumSoundsFor:ONGENERALORDERISSUED 3
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONGENERALORDERISSUED_0"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONGENERALORDERISSUED_1"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONGENERALORDERISSUED_2"
NumSoundsFor:ONSELECTED 3
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONSELECTED_0"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONSELECTED_1"
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONSELECTED_2"
NumSoundsFor:ONSTARTPHASEJUMP 1
SoundID "CAPITALSHIP_TECHBATTLESHIP_ONSTARTPHASEJUMP_0"
MeshName "CapitalShip_TechBattleship"
ExhaustParticleSystemName "Exhaust_TechBattleship"
ExplosionName "CapitalShip0"
CommandPoints
StartValue 0.600000
ValueIncreasePerLevel 0.200000
weaponCooldownDecreasePerc
StartValue 0.000000
ValueIncreasePerLevel 0.030000
weaponDamageIncreasePerc
StartValue 0.000000
ValueIncreasePerLevel 0.050000
HyperspaceChargingSoundID "HYPERSPACE_CHARGEUP"
HyperspaceTravelSoundID "HYPERSPACE_TRAVEL"
EngineSoundID "ENGINE_TECHCAPITALSHIP"
formationRank 0
minShadow 0.000000
maxShadow 1.000000
Hope this helps