Quote Originally Posted by jimmys1 View Post
I have a US garmin nuvi 255W. do I just switch the image here with the one currently on the garmin? when do I use the unlock code? thanks for any help
Yes. Just copy it to the appropriate folder on your device, and it will overwrite the previous version.

You may wish to back up the old map first. And you need to ensure the new map has the same name as the old map eg gmapprom1.

You run the unlock prior to installing the map (img) onto you 255w.