Unfortunately I don't know how to tear down the inside, but will watching closely as I would like to know as well. How do you know your stanchions require re-bedding? Do you have leaking or can you just see that they are working loose?
I've seen a few places on the net where re-bedding was done with butyl tape instead of silicone, might be worth looking into as it seems to be a superior solution, allow more stretch of the bedding material before failure.
Here is a good link that explains the differences and how to:
http://www.sailnet.com/forums/gear-maintenance/63554-bedding-deck-hardware-butyl-tape.htmlSteve.