not to terribly bad, as Rob said most of the tabbing isnt to tough to get at. Once the foot well if out you can access most of it, you WILL need the deck of because it DOES need stringers . . . they all do.

There really isnt much holding these decks on, at least the ones I've seen. Just some tabbing slapped on hear and there and a bunch of screws around the shear. It allows you a ton of working room instead of standing on your head trying yo get to things.