This is a Mapsource installation, install Mapsource software , put the folder above in C: \ Garmin and run install.bat- After that this map will show in Mapsource, from Mapsource you can select it and send it (.img) to your gps as .img format.
If you have patched MS ,you can send it to your pc instead of sending it directly to gps and rename it before transferring to it ,coz Mapsource could replace an existing map (gmapsupp.img) in your gps, if you already have a map named gmapsupp.img inside.