Here are some pics for anybody who's interested....
Flywheel needs removing as the bearing won't fit through the hole, for a WBX you need new bolts and an o ring ( oiled with a little fresh oil) and a felt ring. ( Parts all available from Brickwerks)
I replaced the oil seal at the end of last year when the engine was out but this would be another thing I would recommend doing while the flywheel was off.
then fit an M8 Rawlbolt through the bearing, and expand it, you don't want it too far in just past the bearing, I added a nut to stop it coming out.
Then drill a 20mm hole in a block of wood large enough for the rawlbolt body to slide through, add a large washer and tighten.
New bearing was tapped in with a wooden drift.
As the gearbox nearly fell on me when removing it with a trolley jack I added some eyelets ( I used existing holes but worth drilling some I think) and used ratchet straps to refit the gearbox.
