1.Go to the old map folder and copy the MapUserPatch.dat file to your PC;
2.Then update your map to a new version or another map;
3.Copy the MapUserPatch.dat file from your PC to the new map folder on your TomTom;
4.Use the 'Operate my START/ONE/XL/GO/DEVICE' function in TomTom HOME. Calculate a route to any destination using the new map;
5.Disconnect your device using the 'Device > Disconnect Device' option in the TomTom HOME menu;
6.You can now use your own MapShare corrections with the new map..