Replacing Window Seals

[Dreamweaver]

I have an '88 560SL that needs new rubber around the pillars and windows. I asked my mechanic about it and he asked his buddies that do this kind of work and they told him it's a "nightmare", and very expensive.... sounded to me like they didn't like doing it.

Wondering how difficult this is, if I should tackle it myself, and what the prices are. I looked at the parts catalog but had a difficult time determining exactly what it is I need.