Once the wheels are removed from the frame place them on your working surface. The basic idea is to take the most worn wheel and swap it with the least worn wheel, and continue.
The pictured swap order (going up/down 2 slots and to the opposite boot) is a common one.
Use the paper towel to brush off the wheels and frames.
It is possible to damage the bearings by getting fibers from the paper towel or dirt stuck in the bearings. Use caution when removing dirt from the bearings.
This is a good stage to do more comprehensive bearing maintenance, if desired. Specific procedure varies depending on the model of bearing, so most companies have information on their websites.
Reinsert the wheel into the frame. Align the wheel with the frame and add the bolt back into the wheel.
If the wheel is aligned with the frame but the bolt will not pass through, it may be because the bearing within the wheel is out of alignment like in picture 3. Bump the wheel or carefully use the allen wrench to realign the bearing.
I can get one side of the bolts off but not the other side. They just keep spinning when I try to loosen them. Any ideas on how to get the rest of the bolts out?