[twindman]

There are 2 kinds of seals. One are just the spongy rubber things that compress when the slide is closed. I think you are probably talking about the 2-3 inch flaps that fold in or out as the slide moves.
If the flaps, they are easy to remove and replace, but you have to get on the roof or a ladder. It has been a while for me, but I think there is a screw at the top that goes thru the rubber to hold the seal up. Just remove this and the seal can slide out. Replacement is just the opposite.
I bought a long roll at the dealer and cut to the length I needed.