here is a tip for anyone who uses a single shaft motor to run their wheels on like i do. to make the wheels come off and go on easily, take a narrow blade that will easily fit inside the hole and lightly scrape around the inside testing the fit until the wheel goes on a little easier. make sure the blade is perfectly straight and long enough to scrape the entire surface.
it would be best to wait till you get ready to redo the wheels so you can true them up again.
i know i have posted this before but here is how to true the wheels.
take a long board that you can set at an angle under the wheel and have it resting on the bench.
with a piece of 24 grit paper attached bring the board up to the wheel until it just makes contact.
lightly press the abrasive to the wheel and slowly remove a little at a time and avoid just pressing it up against the wheel and holding it there.
if the wheel is out any at all you will just make it worse. you have to take a little at a time until you get the wheel true. when you are done you should be able to hold your thumbnail up close (and almost touching) to the wheel with it spinning and not see any runout.