Use a 30mm, 6-sided regular socket to remove the pinion nut (avoid the 12-point sockets - too easy to strip the nut and impact sockets are often too thick to fit down around the nut - and if you have a VW, this is the same size as the front axle nut), count the number of turns needed to remove it and reinstall with the same number to retain the pinion bearing pre-load.   (2/8)