You don't need anything other than ordinary tools to service the headset bearings. Basically, you simply have to remove the fork, which means removing the front wheel and stem with handlebar. You remove the headset top cap and then loosen the stem clamping bolts to slide it off the top of the fork steerer tube, after which the fork will slide out the bottom of the frame head tube, permitting full access to the headset bearings. Remember to put all the parts back the same way they came off.