Not a big deal, but you will have to get under the car for access to the bottom mounts. This is a good opportunity to replace the mounting bushings too. The real trick is evacuating and isolating the system so you don't leak moisture into it (use rubber corks on the tube ends when you disconnect them and draw a good vacuum before re-charging. The other trick is to fill it with the right amount and type of oil. Finally, you need to decide whether you will bite the R134 bullet. If so, replace the o-rings with the newer ones for R134.