This is a straightforward demo of how to disassemble, clean, grease, and re-assemble a skateboard bearing. Just in case you wanted to see it done. It's actually terribly easy if you've done it once.
Step 1: What you Need
Acetone or other solvent. (97% Isopropyl Alcohol is good too.)
A bowl or cup to put it in.
A small pin or straightened staple to remove the bearing shields.