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:
Don't know where the Garry's Mod folder is or how to extract zip files? See more useful installation tips.
Onii-chan reqlo, Anu, Mr.peyang, Flusha, AllisterD53, mouiimdz, Vanoss, TheBootyNoVex, Travis nowhere, aryawicaksana090203, gerashchenlo, D3ni4lX11, killer2004 HUN, dncks3317, Poujoshy, pinguino973, Spency Dot Morth, Filipinoy boy, kgergo5800, kgergo5800, Pipepe, chickenmama72, yusuf42yusf, sssss_23, Korchagin2005, Midnight Wolfang, doutrouniverso45, pathlessv7, danil.crasnoperov, Skeetmastr, THE_DKOG, neshisbest95, bradobedencio, DerGami33, pomnisebia, Diegoisawesome, Diegoisawesome, w900ise, catslover565, thanhhoangake, ramicorreu, kghadieh, stryker, iancu9234, SergioGtUno, elbuenzamaritano, zach.mcmanus123, artem10112005, artem10112005, artem10112005 +579 others
