so you want to use the model
ok here is how to do it step by step

1. Make sure the wad is in your addons folder (You can't use the model without Max's Wad)
2. Move the folder VWRR to your models folder
3. open models.dat in notepad (or any other text editor your computer uses)
4. Make a new line and paste "MAX VWRR/KMAX.md3 3.0 0.0"
5. Save models.dat and make sure you have legacyGL enabled and models turned on