Removing the differential, gearbox and torque tube was not as difficult as I expected. I removed the parts as one assembly. I used a jack for the engine, a jack for the torque tube and a transmission jack for the rear subframe and differential. The torque tube slid out of the bellhousing easily, and I adjusted the rear transmission jack so that it kept the whole assembly in balance as I removed it from under the car.
I forgot the fact that the rear subframe is attached to this assembly only by one single point - the differential mount. It is not designed to take this kind of load and was damaged, fortunately I had a new one ready.
I disconnected the rear brake lines and removed them, as I found it stupid to bend brake lines this much to get past the drive shafts. I will reroute the brake lines before reassembly. I see no logical reason for the brake lines to run down and behind the rear differential, when they can simply be routed directly to the pickup points in the wheel wells.
The most challenging task was actually to remove the bellhousing, as the bolts were difficult to access. I've previously done the same work on a BMW 1 series, so I knew a combination of extenders and u-joints would work. I was relieved to discover that, unlike in the BMW, there were no bolts on the very top of the bellhousing!