Jason,
Thanks for posting.
My advice to you is twofold...
Find a local climber and hire him to do it. Make sure it's someone who's at the very least insured. Liscenced and running a business or already working for a company would be great.
You don't want to tackle that on your own, especially not without training and equipment. It *IS* a confined area, and you're thinking about it wrong.
You shouldn't think as "what's as little damage I can get away with". The way to think is "how can I get this done properly, with NO damage at all?"
Since you haven't shown a picture far enough back, we can't see just what kind of a confined space it is. I wouldn't even attempt to give you advice on doing the actual job. It's dangerous, could prove to be fatal, or at the very least, leave you with costly repairs.
Please find someone qualified, even find a couple quotes if you want, and be willing to shell out a little bit for a propper job.
