How to Crossmod and bypass in the same thread.
For those people who don't know how to crossmod and/or bypass here it is.
Since you need to bypass for crossmods, i guess I'll just show how to, if @
supercarz1991's way of bypassing was unclear.
This is an updated method on how to crossmod.
Credits:
supercarz1991 for his bypass method thread.
B1ackAnge1 for his ResHacker tool.
Bypass
Ok you need to delete a useless CA .rez file, for example, PREFABS.rez or TEXTURESCRIPTS.rez

Make a folder of PREFABS.rez or TEXTURESCRIPTS.rez

From there on RezExtract the .rez you're going to mod, for example GUNS_T_PV_AR.rez

Now from there you can photoshop, etc.
Once you're done, put your modded GUNS_T_PV_AR.rez FOLDER into your PREFABS.rez or TEXTURESCRIPTS.rez folder
WHAM You're done bypassing.
Crossmodding.
Now RezExtract A Model, Sound, and Texture .rez file of the same category.
EX: GUNS_M_PV_AR.rez and GUNS_T_PV_AR.rez and GUNS_SND_PV_AR.rez

Now find these model files for the gun YOU HAVE, in your model folder:
PVMLA
PVMLA_W
CM_HND_SP
PVMSH
ANIBASE
Files that have these ^ names are old guns that have been in CA since the beginning of CA.
These are G36E models:

For "newer" guns:
CM_HND_NM
CW_HND_NM
CM_HND_SP
CW_HND_SP
ANI_G
These are CZ805 Models:

Now simply rename with the gun you want to crossmod with.
If you want to do (old gun) into (new gun) simply rename according to this:
PVMLA>CM_HND_NM
PVMLA_W>CW_HND_NM
CM_HND_SP>CM_HND_SP
PVMSH>CW_HND_SP
anibase>ani_G
For sounds rename the WHOLE folder
EX: M416 into CZ805

For textures:
rename whole dtx file.
For example:
PV_AR_DF_M416_BC.DTX into PV_AR_CZ805_HM.DTX

Put your modded SOUND, TEXTURE, AND MODEL FOLDERS INTO YOUR PREFABS.rez folder or TEXTURESCRIPTS.rez folder, and you're done.