you have to open the zip file and put separate file in your add-ons folder.
Stop trying to suck his rooster. These weapons suck, and most DM servers STILL use Bushido's Tier+Tactical because it has more balanced weapons, and they aren't poorly packaged.
Ninja-but-not-ninja edit : Heedicalking made his own humvee, and it was a simple coincidence. GCat's has sharper corners and a camo texture, whilist Heedicalking's has round corners and is bigger.