How easy is this to do? Is it possible to simply remove it straight out the front aperture?

No you will have to dismantle the gearbox, the layshaft must be removed to let the laygear drop down to allow clearance for the input shaft to be removed from the front.
I put a rebuild kit in mine last month
Steve.



[Edited on 25/11/08 by stevec]

Sadly, thats how it looked in my manual. Oh well.