I brought my H3 in for an oil change, and had them install the mud flaps at the same time. The job was completed within 1 hour and they did not need to remove the wheels (that I am aware of). Anyways, how long does it really take to remove 5 lugs with an air ratchet? Maybe 1 or 2 minutes per wheel!
The service guy told me it would take awhile because they had to remove the plastic wheel flares/fenders (not sure what they are called), but the job was still done within an hour, including the oil change..