No need for dealer interface. Mine is a 2007 and complained today that it needed replacing!.
1. Take key out of FOB
2. Use a small flat blade screwdriver to separate the case (pry at slot near the key hole).
3. have a new 1632 battery ready.
4. lift circuit board out of shell and turn over.
5. Remove dead or weak 1632 and replace the same way with new 1632.
6. Put the two halves back together and snap them to close.
7. Reinsert key.
8. DONE! Faster than I took to write this!!
It's also explained in manual on about page 29 I believe!