Not done it myself but here's some advice I found
Rear Beam - Best taking the rear beam off completely after my experience, blow torch the four beams, personally do one at a time, keep an eye out for things catching fire like wires etc. The metal inner case should fall out, if not hammer out, then there is a plastic case sitting in the beam on the out side of the rubber, get a small hacksaw and cut through it, then hammer and chizzle it till it bend and falls out.
Copper grease the new bushes and they simply push in, not the ones closest to the front of the car push upwards, the ones at the rear of the car push downwards, and make sure the metal massive washers go back on, you will see them when taking bolts out of rear beam.