The way we do it is thusly:
1) Deflate the tire until you are able to push down on the sidewalls and it comes away from the rim.
2) Remove the ring. A large sqare-ended prybar or tire iron will do nicely. Be very careful not to damage the rim or the ring. You may need liberal lubrication.
3) Carefully remove tire from rim with a rounded ended tire iron (you will have to pop the sides of the tires off of the rim.
4) Wipe hands on pants.
