Spartuz

Hi All, Reticently got Arma 2: CO and need some help installing missions made by community. I looked everywhere but couldn't find a straight answer even here. After I download single and/or coop mission .pbo files where do I put them and how do I enable them in game? I tried following Armaholic.com "How to install and launch addons" but nothing works. Also tried putting .pbo files in Arma2/Missions folder still nothing works. Appreciate your help! Cheers