Took the top off - a screw with a square (not phillips) hole in the back starts the disassembly. The rest is very straight forward. To get the gears off the main shaft off one lock ring must be removed.
The grease is the most obnoxious thing to remove but it must be all removed to get any "chips".
Examine the gears carefully for any wear and order new ones, replace the damaged parts, pack with grease on all wearing surfaces, and reassemble. The old gaskets were fine - reused them. The new parts look sturdier than the old ones. We use our mixer daily - and knead double batches of heavy bread dough - and also grind sausage - so wear is not unexpected. But my wife and daughter-in-law love their mixers. Parts were very reasonably priced considering the cost of a new mixer.