I have installed one of the suspension bushing sets in a customers 01 Focus a while ago. Installed them with a set of Konis at same time.
Installing the bushings, is time consuming and pretty messy (messy - ie working with the suspension grease, etc) but its very worthwile to install . Just be sure to have some hammers, drills, vice, etc and a good socket set.
If you have a press to push out the rear control arm bushings that would make life even easier.. But, we didnt at the time so we just drilled the material out, then pounded them out, and put the new ones in..
I did mine when i put on my fk suspension. Installation was straight forward and not very hard. I have yet to install the control arm bushings but will be doing so very soon. The ride is very nice. BTW....the grease is nasty, dont get it on your clothes.