You shouldnt require the spider unless the old one is cracked or broken.
As for changing the bearings.........
Power off, remove covers. Disconnect drive belt, remove drive pulley. Remove heater, thermostat and pressure switch. Check if drum splits at front, rear or the middle. If at front or middle, drum will prob. need removal from machine. This involves dismantling the suspension and damping system and removal of door seal and concrete weights. Undo the drum fixing system - either a clamping ring or a series of peripheral bolts and split the drum.If the drum splits at the rear, removal from machine probably not required. Remove the clamping system and pull off the rear plate. Seal and bearings will come away with the plate. Seal needs to be dug out with a suitable lever and the old bearings hammered out with a punch from opposing sides of the backplate. Refitting is, as they say, a reversal of the above process.
Thats it in its briefest form. You do need to have significant spanner skills. If youre the type of guy (or gal) who works on their car, it would be no problem. If you're a novice, dont even go there, get a professional to do it, but its going to have to be a judgement call taking into account the high labour costs (at least £120) and the condition and value of the machine.
Check out www.2ndwave.co.uk/manual.html
dannyboy, October 2008
