i found it easier when fitting a replacement engine, than when i was replacing the clutch with the engine in suite, found it so much easier fitting the gearbox onto the new engine,with the whole lot dropped out, and i don't think it took any longer, just drop the engine /gearbox/ird onto the floor and drag it to the side, then do what you have to do , i guess it depends if you have suitable place to work, but working underneath disconnecting the g/b and ird is a real pain