OGR Coop mods can be played online with your friends, or by yourself by following this guide.
Installing an OGR coop map packaged in a zip archive (zip file)
Extract the contents of the downloaded zip file. You should have a .bundle file and a .bundle.log file, put both of these files in the custom_levels folder in your GRAW installation.
Installing an OGR coop map packaged in a executable installer (exe file)
All you have to do with an installer is make sure it points to the GRAW custom levels folder. For example if your games are installed on drive D: it should look like this.
d:\Program Files\Ubisoft\Ghost Recon Advanced Warfighter\custom_levels
What you should end up with is a pair of files for each OGR Co-op map, placed inside your custom_levels folder - see the image below for an example of 3 installed OGR mods.
Playing OGR coop map.
To play an OGR map yourself simply start GRAW, and select the Multiplayer option. On the next screen select the LAN Server button at the bottom.
This will present you with the server options screen. Click the Start Map button, and select your custom map from the list that is presented. If the map does not show please check you put the bundle file(s) in the correct folder, and check the mod's readme file if there is one.
Now click the Create button to launch the game.