and why do my posts disappear overnight?

m47 is the 5spd right? I have done the 4 spd with overdrive, quite easy really. The 5spd is probably lighter and shorter so should be even easier. It will help to get the car nice and high on jackstands if you don't have a lift, and use a trolley jack to supprt it as you pull it back. Consider doing a good clutch inspection while you are in there, although personally I have never burnt out a clutch on a 240. Do take a look for flung oil around the front of the bell housing as this is a sign the rear seal needs doing and this is the time to do it. Careful on the way back in you don't want to bend the shaft. Also on the 240m it helps to loosen the front engine mounts so that the engine rear can lower a bit, this gives you better access to the bellhousing bolts and makes getting the tranny on and of easier. No idea why you posts disappear but there is a place on the site for tech problems under the HELP section.

Patrick's post was right-on, but I should add that this thing is NOT light.

Unless you are a lot better man than I am, you need a proper transmission hoist to take it down and put it up or you need a couple of strong helpers. I did one alone once with a hydraulic floor jack and I will NOT try that again.