This outlines the front trailing link bushing install ie the STi Group N ones. This pertains to the front only- the rear actual resides in the knuckle and I'll post a seperate tutorial on those.
First these are metal lined bushings, housed in a metal link- it takes tremendous force to get them out/in. You'll want a minimum of a 20 ton press IMO. You'll also want the approaite "special tool" or a reasonable facsimile of.
The trailing arm is only attached by two bolts (17mm), but can be tricky to remove (the front- as there is not much room and little room for air tools). I've got a little "trick" to ease it out.
First remove the three (12mm) bolts that attach the parking cable and ABS cable- pay attention on how everything is assembled- or leave one side untouched to refer to. Loosen the rear nut- you can get air to the bolt side. Next give the front bolt a go- if it won't come remove the entire bracket- just three bolts (also 17mm) and accessible to air. With the bracket (and front of trailing link) removed, remove the rear bolt and the arm is out.
Pic of the rear of the trailing arm and one of the front (you can see the rearward two bolts of the bracket (there is one forward as well).