A garden tractor tire can go flat, leaving you with a lopsided tractor. Sometimes it is a slow leak and you don't notice until one day you realize it is not cutting your lawn level, but rather, it's cutting with ridges. At any rate, changing your tractor tire is really pretty simple if you have a couple of tools.
Roll your tractor onto a flat surface where you can mount a car jack underneath it to jack it up. Of course, the garden tractor is much lighter than a car so even the smallest car jack will have plenty of power to lift your tractor. Place the tractor in park and set the brake. Set the tire chocks in place behind the set of tires you are not working on.
Set the jack in place under a support close to the tire that needs work. Pump the jack until the tractor tire that is flat is rotating freely. Give yourself a little extra room since the new tire is going to be fully pumped up and will be a little taller than the flat tire.
Pull the cotter pin out from the middle of the flat tire. You must use a set of pliers to get to it. Set it aside since you need to replace it after installing the new tire. Remove the old tire and set it aside to be repaired or discarded.
Slide the new tractor tire in place, making sure it is facing the right direction (with the air nozzle on the outside). Slide the cotter pin back in place and release the jack. Pull the jack out from beneath the tractor and remove the chocks from behind the wheels. Your new tire is now ready for use.