Let the air out of the tire. Push the bead of the tire down intothe rim and using a big flat screwdriver or tire iron pry the bead upover the rim. Work another screwdriver or tire iron under the beadand work the bead off the rim. do the same for the other side.To put the new tire on do just the opposite.If you have tubes in the tire be very careful that you don't pinch thetube and cause you more work. Air up the tire and check for leaks.If the tire is a tubeless then you have to seat the bead on the rimwhile you add air. If the bead doesn't do thisautomatically. Wrap a cord around the tire in the center of thetread and tighten up on this so that it forces the bead out on to therim and add air. Add just enough to keep the tire on and carefullyrelease the cord. It will be very tight now. Now add air tospec's and check for leaks. YOu can use one of the ratchet loadstraps instead of a cord to seat the bead.New tires can be very difficult to mount. Be careful that youdon't damage the bead or catch your finger under the bead.Good luck.