Tom,
Changing the mounts took a couple of hours - and part of that time was spent running to the hardware store to makeshift a mount puller. I followed the advice of someone on this board and at this link
http://hsb.baylor.edu/html/easley/mercedes/welcome.html. Other than pulling the old mount from the subframe, the job was pretty simple. I still need to change the differential mount, and then I'm going to tackle the front end.
Ryan