So far I have the mixer completely torn apart and all the old grease with metal fragments cleaned out of the mixer. It is now a simple matter of replacing the old gears with the new ones and refilling with new grease. I will do this if I ever get the new worm gear that is lost somewhere in the Fedex system. Appliance parts has sent another one on its way but will be somewhat delayed due to the holiday. Hardest part of this type of repair is to spotlessly clean out all the old grease. I highly recommend doing it though as your new gears will last far longer. This will be my third gear replacement and I always replace all the gears except the lower planetary gear which has only needed replacing once. If you've spent the time, replace them all.