Go buy this solvent called mineral spirits. DO NOT USE RUBBING ALCOHOL OR ACETONE, these will dissolve a small amount of metal in your bearings and will eventually cause them to seize.
You should first open the bearings. Look around the inside edge for a little ring. It's between the bearing shield and the housing. This is a c-clip. look for where the clip is separated and pluck it out with a safety pin or something with a sharp point. Take off the shields.
Put your bearing in a sealable container along with enough mineral spirits to cover them all.
Shake about as hard as you would normally wuck wuck wuck it
remove bearings, place each one on the tip of a pencil and spin until each bearing is dry.
Buy a small tube of Super Lube, and place a drop or two in each bearing and spin until the inside is evenly coated
Replace bearing shields and c-clips
Here is a cutaway of a bearing to help you out.
Already posted a number of times in various places; thought I should make a topic I could link to whenever the subject comes up.