Injecting works just fine, but, there are a few modifications to the process. Follow the following steps:
1. Download the mod, extract, inject, etc.
2. Back up PREFABS.REZ
3. Rename the injected .rez file PREFABS.REZ
4. ?????????????????????????????????????????????????? ????????????
5. Profit.
Btw, you don't have to do this if it's just a texture mod.
Solved @Eminem