1. First you need a copy of the radio software update. (I used the last 50.00.07) It will be usually in .ISO form. I found it easily doing a google search.
2. Download the latest copy of Garmin City Navigator North America NT Unlocked. (I used 2014.10) You can find it on most torrent site.
Here is the tricky step:
3. Mount the .ISO file on a virtual drive (I used Daemon tool. Its free) and open it to see its content. Copy all the file to a new folder on your computer. Lets call this Folder "Radio Update"
4. Copy the file gmapsupp.img from the newly download folder "Garmin City Navigator North America NT" to the folder called "Garmin" inside the "Radio Update" folder. Once copied inside the "Garmin" folder, rename it gmapprom.img. (the one inside the "Garmin" folder)
5. (optional) if you have the junction view files, create a folder called JCV folder inside the "Garmin" folder and copie the JCV file in there.
6. Now you need to burn the content of the "Radio Update" folder on a DVD. Burn all content and not the "Radio Update" folder.
7. Insert the DVD in the radio unit and wait for a long time. It took me almost 2 hours to complete all updates.
Do this update with the vehicle running or a charger on the battery. You can not interrupt the process. Starting the vehicle will interrupt the process.
It did not ask me for a code for the maps.
This process updated all my maps and the radio software at the same time.