replacing old windows including rotting trim?

I just bought an older house which needs replacement windows. I would also like to replace the sills and side framing around the windows. Is this a difficult DIY project? The house is stuccoed, so I imagine I have to break away the stucco to get to the wood framing. ( i would have to pay someone to re-stucco the finish trim so it looks nice. I hate to have to pay $200-300 per window just for the installation, in addition to the cost of the windows. If it's doable, I could then do it one window at a time on my own. - Does this plan sound feasable? Bob at rgfray@yahoo.com
Bob, February 2006
I may have to replace some of the wood surrounding the windows. Can I just resize that opening with 2x4's or 2x6's so stock size windows (cheaper) will fit? also the 2 exterior door frames I have, have splits in the wood (and some rot in places where screws aren't holding the storm door opener very good anymore) which is decreasing the security of the locks. At least one of the doors is okay to use. The front door sill board that you step on isn't in the greatest shape either. Can I do the same thing, just replace the wood around the frame-fitted to the proper door size?

Bob, May 2006
dead easy no hard work involved, measure opening get new window made, tell the maker the exact size of opening they will make window to fit a little smaller fix your new window with expanding sealer, job done. if you take your time dismantling then very little repair will need done to plaster or rendering.

willie, March 2006