No, this is a different guy who posted this one.
Now, where are you looking? I'm assuming Windows Explorer?
Mine is:
C:>Program Files>Codemasters>Operation Flashpoint>Addons
If you have to, go to Avon's FAQ.
Anyway...
If you have WinRAR, highlight the PBOs and right click. Choose "Extract to the Specified Folder". Then, follow the path to your Addons folder.
If you have WinZIP, highlight the PBOs and (assuming you have Windows) cllick the "Move this File" button at the top of the left hand menu. Then, choose your Addons folder from the list that comes up.
I hope that helped. If it didn't, go to Avon's FAQ.