Virtually all lawn tractor tires are low-pressure cousins of automobile tires, which means unlike automobile tires, they are far more flexible, particularly in sidewall construction. Fortunately, no specialized equipment is needed when removing a lawn tractor tire from the rim. This task will require you to get down on your hands and knees for a short while when removing the wheel from the lawn tractor. If you are not capable of this or don't feel comfortable in this position, you will either need to have someone help you, or you'll have to call in a professional to get the job done.
Place a wooden block roughly the same width as your tire underneath the axle for support. This will keep the tractor level and stable when you pull off the rim. Use gloves to protect your hands.
Drain air from the tire by using the corner of a flat-head screwdriver to press on air valve inside inlet stem. If the tire is already flat, go to the next step.
Remove cotter pin holding tire to the axle by bending the ends up with your pliers and pulling out. Once the cotter pin has been removed, pull tire off the axle. The wooden block underneath the axle will support the front end for later installation of the new tire.
Press firmly with your gloved hands on the sidewalls to break the bead between tire and rim. Flip the tire over and break bead on the other side.
Insert one screwdriver underneath the front sidewall and pull it up and out over the rim. Leave screwdriver in place.
Insert a second screwdriver next to the one already in place. Begin sliding it along the rim while prying the sidewall up and over the rim edge. Move slowly and carefully around the rim, and when you are about halfway around, the tire will literally pop free.
Insert a screwdriver under the rear sidewall exactly as you did on the front one, then insert the other screwdriver next to it. Using the same technique, move slowly and carefully around the rear sidewall until it too pops off. The old rubber will now be in your hands.