My 705 shows as an external drive. Go into that drive, the Garmin folder, and delete gmapsupp.img to delete that map. Be careful to leave gmapbmap.img and fs_image.ver alone!AppleYak said:
If you load an SD card, it will be detected by Mapsource and will be another external drive. You can move the above image to it and the 705 will use it just fine. When you upload via Mapsource, you will have a tab on the top to choose where to upload, main unit or SD card.
It is very smooth and easy. You can get 4GB cards for little money. I have selected areas of Garmin Topo and City Nav, that CA Topo, and Ibycus from GPS File Depot all loaded in my 705.