How to move or copy favorites from one Nuvi to a new Nuvi
The procedure is quite simple. On the old GPS, locate the file named Current.gpx and copy it to your computer. It should be in a folder named GPX.
Now rename this file Temp.gpx and copy it to the same location on your new unit. There may already be a file of this name there, but it's safe to delete it and replace with your new file. When you start up the GPS, it will import all of your favorites.
Now this assumes that your new GPS doesn't already have any favorites on it. If it does and you follow the procedure above, the favorites from your old Nuvi will be ADDED to the favorites on your new Nuvi. If this isn't what you want, copy the Current.gpx file on the new unit to your computer as a backup before you begin. Now, on the new unit, go to Menu > Tools > My Data > Delete Favorites. You can either select them all or delete only the ones that you want to remove. Now use the procedure above to copy favorites from your old Nuvi.