When I did it, I found I could get away with removing all the bolts except the top ones, which were just loosened off a fair way. That let me swing the ancilliaries carrier away from the door far enough to get a lolly-stick-type scraper in there to get all the old self-adhesive remnants out of the bottom and sides of the join. Most of the old tape just fell out, but it was still stuck in places.
Not having to take the glass out was a major advantage, both in terms of the speed of doing the job and the complexity of it.
There's really not a lot of advantage in sealing the top edge of the carrier as there's no way that water is getting in at that point and if the door fills up that far it's going to leak out of the speakers first!