Turn it on, stand back, and start spraying WD40 until the can runs out or it shuts up. You could also take it apart and try the "right" way, but this might be more fun.
Taking apart a bad bearing to attempt to fix it will not likely cause any further damage ... can't break it if it's already broken. Any grease or lube will help, but stay out of the kitchen & bedroom - find something from the garage.
Good luck with your vac ~
