I have just changed mine. I ordered new bearings C00013563 and C00044765 from Merloni Service UK tel: 08709 077077. Cost £31.73 including vat and carriage.
The torx screws are held in with a locking compound hence they are very tight to remove. Suggest you buy a good quality T40 bit at least 5/16" hex size. You need a good 1ft of leverage on the centre spindle screw. Use a piece of wood jammed in between the pully and spider to stop it rotating.
My 1/4" hex T40 bit shattered when I tried to undo the screws.
You can knock out the drum spindle with a heavy hammer, but put a piece of aluminium plate on top of the spindle to prevent damage. Wood is no good it just splinters.
Once the spider is free you can knock out the bearings. There is a seal one side. Do not try to lever it out. Knock out the bearing and it will just fall out with it.
When drifting in the new bearings do not hit the centre race, only the outside one. Refit the seal and apply grease. I used a high temperature one.
It took my 2 hours in total, mostly because my tools kept breaking trying to undo the very tight screws.
Andy Willey, November 2004