ShackTac Fireteam HUD (STHUD) in ARMA 2 & OA - ADDONS & MODS: COMPLETE Posted August 18, 2013 1. Downloaded CBA file and placed it in the main Arma Directory. 2. Downloaded the Hud file and placed in the main Arma Directory. You're almost there. Just launch Arma, and go to extensions, in there both these mods should be listed. Once you have activated them, you will have to restart Arma and you are good to go. BTW, Welcome to the master race... hehehe.