For how to edit IS cab files i suggest starting learning from these
Tutorials: Useful tools, freeware programs, scripts etc
ISCab Examples (Add and replace files part)
Best its to extract original exe and rename it filename.exe.bak
Then doing IScab add and replace by replacing original exe with cracked and adding filename.exe.bak as new file into cabs so its installed to game install folder also.
example for add and replace list.txt, red text is added after you have made list.txt and cleaned it to only include gamename.exe
note: remember to add correct File[Number] when adding new file, so check what its last file under [SOMETHING] before cleaning it up, if its like File100= then new file is File101= when adding it
Code:
[ISCAB Info]
Product=ISCAB
Version=2.0
[SOMETHING]
File6="gamename.exe" , "gamename.exe"
File8="gamename.exe.bak" , "gamename.exe.bak"
Here is also similar question answered
Jericho; replace files in installation package
EDIT: I consider it bad choice to make this for games which get lot of updates but good for old games which don't get updates
Good example in my use is Shivering Isles backup which has all DLC + couple mods + preupdated and crack included in cabs.
full list.txt from my Shivering Isles backup
Code:
[ISCAB Info]
Product=ISCAB
Version=2.0
[Plugin]
File1="Oblivion.exe"
File2="Readme.txt"
File3="Data\Credits.txt"
File4="Data\DLCShiveringIsles - Meshes.bsa"
File5="Data\DLCShiveringIsles - Sounds.bsa"
File6="Data\DLCShiveringIsles - Textures.bsa"
File7="Data\DLCShiveringIsles - Voices.bsa"
File8="Data\DLCShiveringIsles.esp"
File9="Data\Oblivion.esm"
File10="Data\Shaders\shaderpackage001.sdp"
File11="Data\Shaders\shaderpackage002.sdp"
File12="Data\Shaders\shaderpackage003.sdp"
File13="Data\Shaders\shaderpackage004.sdp"
File14="Data\Shaders\shaderpackage005.sdp"
File15="Data\Shaders\shaderpackage006.sdp"
File16="Data\Shaders\shaderpackage007.sdp"
File17="Data\Shaders\shaderpackage008.sdp"
File18="Data\Shaders\shaderpackage009.sdp"
File19="Data\Shaders\shaderpackage010.sdp"
File20="Data\Shaders\shaderpackage011.sdp"
File21="Data\Shaders\shaderpackage012.sdp"
File22="Data\Shaders\shaderpackage013.sdp"
File23="Data\Shaders\shaderpackage014.sdp"
File24="Data\Shaders\shaderpackage015.sdp"
File25="Data\Shaders\shaderpackage016.sdp"
File26="Data\Shaders\shaderpackage017.sdp"
File27="Data\Shaders\shaderpackage018.sdp"
File28="Data\Shaders\shaderpackage019.sdp"
File29="Data\Textures\Effects\TerrainNoise.dds"
File30="Data\DLCBattlehornCastle.bsa"
File31="Data\DLCBattlehornCastle.esp"
File32="Data\DLCFrostcrag.bsa"
File33="Data\DLCFrostcrag.esp"
File34="Data\DLCHorseArmor.bsa"
File35="Data\DLCHorseArmor.esp"
File36="Data\DLCMehrunesRazor.esp"
File37="Data\DLCOrrery.bsa"
File38="Data\DLCOrrery.esp"
File39="Data\DLCSpellTomes.esp"
File40="Data\DLCThievesDen.bsa"
File41="Data\DLCThievesDen.esp"
File42="Data\DLCVileLair.bsa"
File43="Data\DLCVileLair.esp"
File44="Data\Knights.bsa"
File45="Data\Knights.esp"
File46="Data\DLCList.txt"
File47="Data\menus\main\hud_reticle.xml"
File48="Data\textures\menus\misc\hud_reticle_small.dds"
File49="Oblivion.exe.bak"
File50="tes_construction_set_1.2.404.exe"