Hi,

let me try and remember some of the details as I go along.
First I mentioned that I did the rear suspension as a 2 stage operation.
First up, in my Garage floor I replaced the sub-frame mounts, the sway bar bushings and the sway bar links. I saved quite a bit on labor this way (used the same principal on the front as well).
Now comes the part you are asking about. I am afraid you are incorrectly assuming the extent of "removal...."
Second stage was with the car on a lift, wheels off, and Sub-frame supported by a transmission jack. To get the trailing arms off, you must lower the Sub-frame, otherwise no access to the bolts. To lower the sub-frame you must release it from the sub-frame mounts. The book says one must lower/remove the Drive Shaft (disconnect) , again- to gain to access to secure the bolts on the trailing arm on the passenger side. Luckily I did not find this to be the case. - When the time came we just wiggled the bolt back into position. Nor did I need to remove the rear differential or exhaust. Just pushed the exhaust aside.
In order to completely remove the trailing arms you do need to remove the calipers, disks, disconnect the axle half shafts as well as remove the springs. We used a spring compressor that I will not recommend in any way. The mechanic I worked with took complete responsibility there- I was very leery of this. Have gained great respect for stored energy. It is also much tighter space than the front. Nevertheless if memory does not fail me - when you lower the trailing arm the spring is released. It is shorter than the front springs and does not have nearly the same amount of stored energy aiming to explode. So it is "simpler" to remove/install.
We took the trailing arms off and worked on them one at a time. Perhaps if I had the correct MB puller I could have done the replacement on the vehicle, not sure. But I needed to put it on a press - so off it came...Some guys I talked too said they would just torch the rubber bushings to get them out. Not knowing enough about Rubber/Metal melting properties, when mixed with gas fumes, I decided to do it the old fashioned way.
I also remember that through the trailing arm runs a Brake Line Cable that has to be released (emergency brake I think). The only thing that slipped by me - causing some damage was an ABS sensor cable that is hooked up from the rear seat and goes to the differential ( almost sure) which I ripped by yanking too hard on the trailing arm -
I think this just about covers it. The change is huge . Just like getting a new mattress. Very enjoyable for a while - then, once you get used to it you loose your point of reference.....Can't remember what it was like before.
In parting words I will reiterate that several mechanics I spoke to before going down this road thought I was nuts to spend the time and money on this old car. I far as I am concerned, I am willing to drive this car forever - and this forum really supported me during the project.
Good Luck to you