STEPS:
1: Choose which version you want to use(If you want Plain version, just go to step 3), either the Plain or 
Taped Grip version.
2: In the RAR of which version you want to use. inside either RAR files, there should be 4 folder
each saying materials, models, scripts, sounds, Extract the RAR file
3: Copy all of these 4 folders(materials, models, scripts, sounds) into your steam/steamapps/your account name/counter-strike source/cstrike folder.

Thats all!! 