if you are going to do it yourself be prepared to spend some time at it and you definitely want to have 2 people.
You will most likely end up having to burn out the old bushing if its not corroded. on the stock bushings they use a metal sleeve that presses into the subframe. The metal will need to be bent or cut out. A shop will charge you crazy cash to do it too from my estimates. If nothing else it is worth buying the Ireland Engineering Urethane ones because you really don't have to have a press to put them in. the slide in and work much better than stock. If you have any more questions about the install let me know as i've done the entire suspension overhaul on my old e30