2003 MDX gps issue / question

Hello all, I am new here...

I am trying to help a friend with her 2003 MDX before going to the dealer. The issues are:

1) Gps keep resetting inself and locks for a while then resets again..
2) Holding buttons 1 and 6 and power on the radio - does not show code.
3) Could not adjust air flow directions.

Questions:

1) How to reset the gps and radio? Currently I only have code for gps.
2) How to remove the radio to get the s/n?
3) How to remove the gps unit from under the passenger seat?
4) If seat removal is required in order to remove gps unit, is there a DIY for it?

Thanks..

Mantist