1. Install sikkmod (see instructions on moddb); you should have a "sikkmod" folder in your doom3 folder 2. Extract Monoxed textures inside sikkmod folder in your doom 3 folder(or base folder to use them with vanilla doom3; still works with sikkmod then) (there should be folders like "textures" etc. inside the base or sikkmod folder) 3. extract the wulfen texture pack file to the sikkmod folder (this should be a *.pk4 file) (you can also put the .pk4 file in the base folder if you want to use the textures in "normal" doom 3 too) 4. do the same with the small fix
5. Launch sikkmod through shortcut or ingame mod menu
NOTE: If you play normal Doom 3 without sikkmod and only with wulfen textures you may see black panels (monitors, door panels etc.) to fix this you have to open the .pk4 file from the Wulfen texture pack (can be done with 7zip) navigate to the "materials" folder and delete the "base_wall.mtr".
NOTE #2: ATI user may have to disable Catalyst A.I. or just simply rename (or copy doom3.exe and then rename the copy) the doom 3 executable to something other random like "doom3 no ai.exe". Just make sure don't name it like the exe of another game ;)