First of all unplug the mixer. Then remove the small screw from the back domed section of the mixer. There are two lugs at the bottom, so tilt it back and down to get it off. Watch out for the electrics inside. Then you have to knock out the cross pin above where the dough hook, mixer blade is inserted (attachment assembly). Use a pin punch and small hammer. Then remove the chrome ring above this, it is a simple pull off job, perhaps with a little twist. You will then need to remove this attachment assembly from the shaft. I use a larger pin punch or drift and tap the end of the shaft whilst holding the assembly. again a little twist may be in order. Once this is off, you will see some screws around the circumference plus 4 more on the underside of the main body. Undo all of these lay the mixer on it's side and it should come apart. Be careful as it is stuffed with a lot of dirty grease. If needs be, ease it off with a screwdriver twisted in beside the speed lever, be careful of the sealing gasket around the front portion and do not damage this. The mixer should now be in two halves. though still connected by the wiring, but enough room to do the necessary gear replacement. Assembly is the reverse, but you will need to jiggle the two halves a little to get the worm drive and gear to engage. DO NOT force it. Patience is the watchword here. If you can't do it first time, have a cup of tea and try again.
Lesbo, September 2009