Read through this last night before going to change the clutch today on a 2ltr 156 Selespeed and thought I'd share the experience.
Most importantly, you don't
need to remove the actuator to take off the gearbox - or the driveshafts.
It was done fairly quickly in about 3 hours to bolting the box back on. I did have the advantage of having it on a ramp - doing it from the floor would take longer but the process the same.
The key is to be able to get the box and actuator low enough to pass under the inner wing and power steering pipes.
From the top of the engine; battery and tray out, big block connector to selespeed undone, 2 hydraulic pipes to selespeed detached and anything else in the way unclipped.
Underneath; Take off exhaust sections from the manifold to half way back (leave on the back 2 sections). Unbolt the shielding plate that carries the heat shield and handbrake cables (doesn't need taking off the car though), which now allows the front subframe to be removed. Remove the front subframe complete with lower wishbone (detach those bits of suspension attached, roll bar link etc). Rear engine/gearbox mount also gets removed at this stage, (can't remember if it came off before or after the subframe now!!) support the engine while you do it and then let it down, the engine only sags down a couple of inches.
Remove all gearbox bolts bar one (suggest large one at front) and starter motor.
Support engine with jack under sump, then unbolt the nearside engine mount (one 17mm bolt, or undo the 4 bolts that connect the mounting to the gearbox. You can then lower the jack til there's enough clearance to slide the box and actuator off. The offside engine mount (and engine steady) flex easily enough and support just fine. Refitting - as they say - is the opposite of removal.......
Only posted this due to being worried how easy it was going to be (or not) and I really didn't want to remove actuator with associated messing around getting it back on and set up. I can now confirm that you definitely don't need to.