Using your Allen wrench or a skate tool, remove the hex nuts securing the wheel to the axle and set them aside in a safe place. Slip the wheel off the axle. Similarly, remove the remaining bearings from the four wheels.
Fill a small disposable plastic container with the citrus based cleaner and dip the bearings into it, making sure the bearings are completely submerged.
Shake the container vigorously for about a minute and then pour out the liquid.
Again fill the plastic container with the citrus cleaner and rattle for about a minute. Once the dirt and grime has been dissolved into the cleaner pour it out.
Repeat the process until the cleaner is no longer clouded by the grime on shaking the bearings.
Once the bearings are clean enough, remove them from the container and wipe down with a rag. Dry the bearings with canned air.
Spray the dried bearings with a lubricant specially designed for skate bearings.
Re-attach the clean wheel bearings, place the wheel back in position and replace the hex nuts. Tighten the nuts with the help of an Allen wrench or skate tool and test your rollerblades on a ride.