Hello,
I made a backup, thanks to your tutorial.
Can you help me, to indicate the steps to update my device.

Information:

DeviceName=TomTom XL
DeviceVersionHW=XL
BootLoaderVersion=55274
ApplicationVersionVersionNumber=9151
ApplicationVersion=605385.2
CurrentMap=USA_Canada_and_Mexico_P
CurrentMapVersion=850.2784

Thanks for the help.

Simply choose a map from the map thread and replace your old map with it.
Use FastActivate Premium to activate the new map and to patch the Navcore (if not already patched).