First of all, I probably could get it done for about $5/each at a tire installer, but I'm talking about doing it for FREE. Can it be done? I would think you could release all the air from the tire, lay the wheel on its side and step heavily on the tire closest to the rim to break the seal. Flip wheel over and repeat. I figured I could then place a smooth, rigid, strong plastic or wood flat bar in the inner rim of the tire and pry the rim over the wheel's outer rim. I figured I could then slide the bar around the wheel's outer rim until the tire was over the wheel. I'd then repeat for the other side of the tire. Crazy?

Sure it can be done, but why if it only cost $5/ea ?

I would be ultra carefull not to damange the tire or rim however.

"slide the bar around the wheel's outer rim until the tire was over the wheel"...is how you ruin the finish on the rim. Good tire removal machines only contact the rim at the hub to hold the rim.

I wouldn't even think about doing that myself. You will definately scratch your wheels no matter how careful you are because those sidewall closest to the rim are very stiff and take alot of force to pry it out all the way around the rim especially with low profile tires. I've seen professional sometime have a hard time doing it even with a tire machine on certain tires because they're so stiff.