I found Dometic seals on eBay for less than direct from Dometic. We have an RM2662 unit and the replacement seals are part number 3108704374. Check your model before ordering. We ordered from hard2findrvpart. The cost was a pricey $117.
The kit ships with double sided tape and a small tube of food quality silicon. I talked with the PM at hard2findrvpart and he advised to toss the tape and get a bigger tube of silicon because they found the tape will release. Lowe’s has DAP Commercial Kitchen Silicone Specialty Caulk which should work.
To remove the doors, you will need two 10mm wrenches. There is a plastic cap topping the pivot pin for freezer door. When that is removed, the mystery of how the doors come off will be revealed.
Removing the old seals will take two hours with a razor knife. The factory seals are installed in a channel and you will have to remove them from the channel. They seals were installed before the two pieces of the door were snapped together. There is no way to unsnap them. Hence the long time to cut them out. Do not try to pull the seal out. You will probably break the thin plastic. And that would mean a new door.
The new seals lay flat on the door, not in the channel. Hence the need for a good sealant.