My way is not only faster then most traditional ways, but its also makes the trailing arm bushing come out without much resistance.
Things you will need:
30mm socket
Bigger C-clamp or PREFERABLY a vise
Box cutter
KY lube (not required, but if you have it I recommend using it)
First Cut off the head off each of the 4 trailing arm bushings:
To remove the bushing follow this illustration (vise can be subbed for a C-clamp:
To push the new bushing in again follow the illustration. Although not required, especially if you are using a strong vise; lube the outside of the bushing and the inside of the trailing arm hole, it makes it easier if you are using a c-clamp.
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Another way to remove and install is this DIY tool from e30zone.net – worked well: http://e30zone.net/e30zonewiki/index.php/Replacing_Trailing_Arm_Bushes
Also, when doing the removal, heat the metal around the trailing arm bushing with a propane torch. This made the job incredibly easier. You don’t need to melt them or anything, just enough to expand things a bit. The above tool will have them out in no time.
Prior to install, clean the inside of the trailing arm tube to ensure smooth traveling by the bushing. When installing, remember to use the soapy water, should be a breeze with the above tool.