I am posting this content as it was originally created by Jon Lofquist (US Nav guru and broker) and shared with the yahoo/AudiNav forum last year. This might also be of interest to the group if you are worried about spilled drinks that could impact the function of your Nav buttons etc.
Here’s a process for cleaning the buttons:
I found this site and thought it might be useful (especially if you are planning to swap the faceplates from the climate control units) etc:
http://zener.com/audi/HVAC_cleaning/
Also worth noting, the Euro Nav+ (RNS-D) is the exact same unit for all Audi models. The only difference is the shape/color of the faceplate (based on year, revision letter and model Audi you drive). Therefore, swapping faceplates can be done if you wish to find the correct
B5 A4/S4: 8DO-XXX-XXX
B6 A4/S4: 8E0-XXX-XXX (the shape of the B6 is also applicable to the B7 A4/S4)
C5 A6/S6/RS6/allroad: 4BO-XXX-XXX
D2 A8/S8: 4D0-XXX-XXX
Process for replacing/removing the faceplate (courtesy of Jon Lofquist) – plan on 1 hour:
1. Put everything on a soft towel.
2. Remove four #8 torx screws from each side of the Nav+ just behind the faceplate.
3. Gently pull faceplate forward and it will come off. Remove the four cables – carefully.
4. Put Nav+ electronics box aside.
5. Put faceplate screen down and remove the two #8 torx screws in the very center. LCD screen will come out the front. Set it aside.
6. Cover the end of the pliers with a soft cloth or towel and use it to pull off the two knobs on the front. They can be a bugger, especially the left one for some reason. Rock them slightly and rotate if necessary. Careful you don't rip up the knob surface.
7. Use an 11mm nutdriver to remove the nuts on each shaft.
8. Put the faceplate back down as it was, and remove the four #8 torx screws holding the metal bracket. Set it aside.
9. Disconnect on each circuit board the red connector attached to the ribbon cable.
10. On each circuit board remove the eight #6 torx screws.
11. Move the circuit boards and switches to the new faceplate and tighten the eight #6 torx screws. Reconnect the two red connectors and tuck in the ribbon cables.
12. Replace the nuts on each shaft. Ensure the switches are straight.
13. Push the knobs back on the front. Very important – Hold the switch on the back as you push the knob on so the switch doesn't push out of the ckt board.
14. Put the metal bracket back into place. Ensure the four tiny clips in the center are engaged. Ensure the cables come through the holes. Replace the four #8 torx screws.
15. Replace the LCD and the two #8 torx screws.
16. Hold the faceplate up to the electronics box and reconnect the four cables. Careful! The flat cable will either require a good firm push, or you can "disengage" the connector, slide the cable in, and then re-engage. Push and wiggle the others into place. Ensure they are in all the way.
17. Ensure the two black cables are folded back into their slots. Ensure the two wire cable is in it's slot too.
18. Start to mate up the faceplate. You'll see how it goes. Double check the cables are in their slots.
19. Mate it up securely and replace the four #8 torx screws on each side.
Again, thanks to Jon Lofquist for documenting this process for the group.