technically it shouldn't be too hard to mod, since it;s on a idtech like engine, but im sure most things aside from texturing swaping are pretty locked down. also i dont think they want people to be able to make there own content and make maps with radient since, they release map packs and a new cod every year, so they…
Figured it out. If you have the steam version go here C:\Program Files (x86)\Steam\steamapps\common\call of duty modern warfare 3\main everything with extension .iwd has textures in it. You can open those files and extract the contents with winrar, they're just a container, 7zip doesn't work for some reason though? Then…