The band saw is without doubt the single most dangerous tool in the shop. Therefore, proper maintenance is crucial. Rubber tires wear out from the heat and friction generated by the rotating saw blade. This combination causes the rubber to become dried out and brittle--a dangerous condition.
If possible, when replacing your band saw tires, choose urethane or neoprene types, as they are more durable. The rubber tires used to be glued on, making removal a challenging process. The newer types do not require gluing.
Unplug the band saw, and let anyone else in the area know you have done so on purpose, so some "helpful" person does not plug it back in. This is a vital safety step.
Remove the upper and lower safety guards.
Locate the tension adjustment screw and knob on the back side of the upper wheel. Loosen the thumb screw (on most types of machines, it will be a thumb screw), and rotate the tension adjustment knob to lower the wheel until you are able to remove the saw blade easily.
Loosen the hub nut on the upper wheel using the wrench. Before you remove it, make a mark with permanent marker to so you will know which is the front of the wheel when reinstalling; it is important not to remount the wheels facing backwards.
Also mark which is the upper and which is the lower wheel.
Loosen the hub nuts on the lower wheel, and also mark it indicating front prior to removal. No further tension adjustments are necessary to remove the lower wheel.
Remove the old tires. If they are rubber, they are likely affixed to the wheels with glue or contact cement. Removing them will take a considerable amount of time. It may be necessary to use a screwdriver to pry under the edge of the old tire, but do so carefully, so as not to damage the wheel itself.
If they are stubbornly adhered to the wheels, you may pour a little solvent under the edge of the tire, and wait a bit for it to work. Gradually begin working the tire free, adding more solvent as you go, if needed.
Clean the wheel thoroughly once the tires are removed. You may need to do some careful scraping, using solvent and rags, or a soft wire brush to finish removing all the old glue residue, being careful not to damage the wheel. It is very important that the wheels be fully cleaned of all such detritus.
Inspect both wheels again to be very certain you have fully cleaned them free of the old tires or other residue.
Place the wheel, front side up, on a flat surface, and begin easing the new tire over and around the edge. You may find that using a pair of screwdrivers to work the tire on (as you might with a bicycle tire) may be helpful, but be very careful not to mar the edges of the wheel.
If the new tires are simply too tight, the first step is to double-check that you have purchased the correct size for your machine. If so, a soak in very hot water may help you ease them over the rims.
Replace the wheel on the axle, and rotate it by hand, noting any high or low spots. If found, this may indicate an uneven stretching of the tire as it was installed.
Remove the wheel again, and carefully "work" the tire fully around the wheel to even out the placement. Repeat with the other wheel.
Re-mount the wheels on their respective axles and tighten the hub nuts. Briefly plug in the machine and turn it on for only a few seconds to be sure there is no wobble in either wheel. Unplug the machine again.
If any wobble was noticed, be sure the wheels are on the axles straight, and the nuts fully tightened down. Repeat this test as necessary until the problem is corrected, making sure to unplug the machine between each repetition of the test.
Check to be sure the band saw is unplugged, and proceed to reinstall the saw blade, teeth pointing downward.
Re-adjust the tension knobs to the proper position and tighten the thumbscrew firmly.
Avoid use of any lubricating agent when installing the new tires, as this may cause slippage and improper function of the saw.
This is not a task that you should attempt if you are unfamiliar with this tool.