It's pretty simple.
Open the Extractor.
Then put it in the CrossFire Rez Folder.
Open it and type RF017.rez
Press 2
Let it extract.
You will get a new folder.
Look the at the dtx files with dtx view.
Get a texture and make sure the size is small or the same as the original texture.
Get the injector and the 'fake' texture in the same place with RF017 and inject.