run garmin keygen 1.5
get your garmin XT Software Unit ID: (go to "About" in Garmin XT)
enter custom map ID 2309 in the keygen after inputting the Software UID
copy the generated key to a file called "gmapsupp.unl" (the 2010.30 file has to be named gmapsupp.img) to your garmin directory.
and the map is unlocked.