Remove axle nut with a wrench, be careful not to scratch or damage the shield. Put the washers and the nut aside for now so nothing gets lost. To pull the bearing out of the wheel use the trucks axle to pry it out, keep rotating the wheel and applying pressure till it pops out. Put your bearings and spacers onto the rag; wipe off as much dirt and debris as possible. Rotate each bearing and take note of any that are glitchy, or need to be replaced.
Put on a latex glove, Take the bearing pick or push pin and insert it at the inner metal ring between the rubber shield and metal. Push in and turn to pry the shield off, if these are skate bearings the nylon shield should pop out with out too much pressure. This instructable
has a video of another way to de-shield a bearing. Collect all the shields and stick a wire through them. Bend the wire to fit the container they'll soak in. On this wire you can include the spacers and washers if they need cleaning too.