Adrien Brody Prop

This download looks like an addon. You need to extract the downloaded zip and put the addon folder in your Garry's Mod addons folder. You should end up with a directory structure similar to below:

• steamapps
  • common
    • garrysmod
      • garrysmod
        • addons
          • Adrian Brody Prop <-- Addon folder!
            • e.g.
            • lua
            • maps
            • materials
            • models
            • etc

• Adrian Brody Prop/
  • materials/
    • models/
      • brody/
        • brody.vmt
        • brody.vtf
        • inv.vmt
        • inv.vtf
  • models/
    • brody/
      • brody.dx80.vtx
      • brody.dx90.vtx
      • brody.mdl
      • brody.phy
      • brody.sw.vtx
      • brody.vvd
  • readme.txt

attlit, [Stealth], img, the spy, gostya66678, chota.americana, a "JOLLY" Male :3, mossesx, grove, The Dastardly Paril, Ryan, SkyboundLight, Warpath-The-Laughing-Swordfish, Steve Balls, Jones Bones, Jackster743, Heckkkkk