Done it on my 40 Ocean (2001) with 120S-E saildrive. The workshop manual (with torque values) is in the download section here. The engine needs to come forward about 5cm. As the engine only has two legs, with the rear resting on the saildrive, it must be supported aft, else it'll fall down into the sump and you'll have a hell of a time getting it back up (my MD22+saildrive weigh ~250 kg total). I've done this with a thick piece of timber that went under the flywheel housing and rested on the aft engine supports. Plus some timber wedges, which are handy for adjusting height when reconnecting it to the saildrive (that's the only hard part - get someone to help you with that).
To move the engine forward, I've tied a rope to one engine mount, looped it around the compression post (with some padding) and back around the other side engine mount, then tied it back to itself with a rolling hitch. Then I pulled up on both middle sections of the rope (between companionway steps and cabin table), which gave me good leverage and the engine slowly came forward. Slide the rolling hitch forward to tighten up the rope and repeat until the saildrive disconnects. The forward engine feet are still resting on the raised GRP they are bolted on, about flush with the forwardmost bit of that.
The prop shaft does not have to come out, you can angle the unit out of the hole (tilt gearbox back - the aft end of the propshaft comes out last). However, you might as well pop it open, it'll make it easier to lift out the heavy gearbox+leg and you want to inspect the shaft for wear and renew the seals anyways.
Oh, you also have to disconnect the exhaust hose from the engine, and the gearbox cable obviously - possibly throttle cable and fuel line, depending on your setup.
