'07 Jayco 23B Bunk End Seals Replacement

I hope to receive the new bunk end seals from the Jayco dealer this week. I've opted to go with the "new" design, which is Jayco part number 0210350, which is a black self-adhesive seal with two "ears" on it. This will repalce the original white seal (Jayco part number 0502453) which has weathered, dried, and cracked in some places.

Question: For those who have replaced their bunk end seals, what surface preparation did you find to work best?

Thanks.