Replacing a gearbox

[sp00k]

Well after much head banging i may have found a gearbox for the mav.However as ive never done one on one of these b4 i was looking for advise on how to do it.I know its a big job as torsion bars need removing and that but i do like a challange.Or my second option is finding someone else to do it.Not sure if anyone can recommend someone who wont charge too much(bristol area).Will also being replaceing the clutch at the same time just to save hassle later on.Also is the box in a LWB the same as whats in a SWB??