Obviously it all on SD card (program+map data) therefore it shouldn't be a problem installing iGO. Download this primo version:

[Only registered and activated users can see links. ]

unpack and copy folder Primo on SD card. Than go to settings on your 2-din and set path to a new software - there should be an icon "nav path" (or something similar) where you can set new navigation path and save.

Make sure that you make a backup of your original SD card, or better - use a new one. 8 GB is perfect.