Remove the drum from the machine.
Use a bearing tool. looks like a big bolt. I fits through the bearing then hit it with a hammer. Must be removed from the back to front as it sits recessed in the plastic drum.
Fit new one is reversal of above.
You may get away with breaking the old bearing but you must use the bearing tool for fitting so you do not damage it.
In a workshop you are talking about 4 hours work start to finnish
Kenny Hilton, December 2004