iv'e done a few over the years but never a golf one although i doubt if it's that difficult.The hardest thing with all of them was getting the new brushes.If you do go ahead and have a little time spare it would be wise to get the comm skimmed but if you cannot do that then get some very fine wet and dry,fold a bit in half as wide as the comm and wrap it around the comm pinching it at both ends to keep it tightly against the comm.Then turn the whole rotor from the other end until the whole comm area is nice and clean.Then use a thin piece of plastic or wood (mc donalds coffee stirrer is ideal) and run it along each groove between the segments of the comm to get any dirt out.Do'nt use too much pressure when doing this as you can damage the insulation.Good luck.