I have used boiling most of the time but seem to need a hobby knife to remove a little of the tire where the bead was still stuck on the rim.

Someone in the nitro offroad section has this thread going also and some guys are saying use a heat gun on high and hold it 2 inches from the wheel while following the bead around the wheel, once you hear the bead letting loose continue for another 30 seconds then with gloves remove the tire from the rim.

I will be trying this soon^