Yes they were replaced with sub frame still attached to car but with trailing arms driveshafts and rear muffler removed. As mentioned I am redoing all suspension and brakes thats why the training arms are off. The trailing arms bushings and rear wheel bearing and rear drum brake cylinders all getting refreshed.
The subframe was initially supported in three places, under the differential, and under each of the left and right bushings.
To do so I did the following. Moved the support near the bushing question to the subframe right next to the big bolt and then also supported the car body under the jack post with an adjustable jack. Note that I have a 4 post lift which makes working on the car a whole lot easier.
The two 13 mm hex bolts and the large 22mm nut are remove from the "push rod" and the push rod removed. Per the manual the large bolt can then be knocked upwards. In my case I used a piece of thick AL (do not want to damage the threads) between the hammer and the bolt end. You will have to remove the respective rear seat to retrieve the bolt. Also in my case the rear seat belt retracter was in the way so I had to remove it to get the bolt out. The upper end of the bolt is serrated. My came right out with a good few hard knocks, but it you have rust there, good luck. Might want to soak it with penetrating oil well in advance.
Once the bolt is out remove the 4 13mm head nuts/bolts. Yes you can get the two outer ones by using 1/4" drive extension and a 6 point socket attached to swivel u-joint. Then it is a matter of adjusting the jacks that support the car and the subframe to free the bushing.
Of course I was so far along I perhaps could have gone ahead and remove the entire subframe but chose not to do so. If I could not get the two bolts to break free that was the option.
Hope this helps.
jjs2800cs