Yes, it can be done.
First you need to have your own ttgo.bif file before activating anything. You can get this file by simply restarting the unit. A new ttgo.bif file will be created.
You also need to delete the .dct file(s) from the map folder before you activate the map.
FastActivate Premium is probably the easiest tool you can use to activate the map, navcore, etc. Run it from the root of the device.