The rubber is indeed bad, you can
almost drive a truck through the gap it left

, and isn't one sharp edge anymore but pieces. Great thanks for the instructions Haasman, so I put sealant just where the glass sets or there and where it meets the car? So it mainly seals on a fairly sharp edge of the roof then?
That is great to hear that it was easy, did you use the rope method that Haasman details? Thanks for the offer Samiam4, hopefully things go smoothly. Next time I order some parts I guess I'll get that as well. It already ruined the foamish piece with the sun visors, I just figured that was from a previous leak.
Thanks for all the replies so far, maybe in a month or so I'll dig this thread up and tell how it went or any complications.