Does the drum have to be removed to rep...

No, remove the drive belt pulley and remove the 8 bolts holding the x shaped cast iron frame with the bearings in, lay the washer face down (ensuring adequate protection to the door and controls) whilst pulling the x shaped frame away from the drum tap the threaded shaft lightly with a rubber faced mallet and the frame will come away complete with bearings and seal. To replace the frame (with new bearings and seal installed) I used a large socket and long bolt to draw the shaft through the new bearings.