NEED HELP WITH ArmA 2 CD Key Change!

I'm new around here and this was my first time buying a Cd Key but I don't know how to change it every video I watch they don't know what there talking about please help.

Message me on skype: James_9797

Hey, a Key Changer was just posted to the forums not too long ago. It's been approved and has 2000+ downloads. It's on the the 2nd page of the DayZ/ Cheats forums. The thread is called " Darky Key Changer/Ban Checker 1.1 [By Darky.Hax]". Or just go here:http://www.mpgh.net/forum/624-dayz-h...darky-hax.html