Navigon 40 Sat-nav

 Navigon 40 Sat-nav with no sound coming from the speaker.

4 small torx screws keeps the cover in place (yellow circles).

Pry the front and back cover apart, using a "soft" tool. The tool I'm using is made out of plastic.

Lift the plastic "lock" (yellow square) in order to remove the flat display connector.

2 plastic hooks (yellow circles) keep the PCB in place. Push them outwards.
Lift the speaker connector (red circle) and the battery connector (green circle).

2 Phillips screws keeps the speaker in place (yellow circles). 

Remove the speaker.

I used a standard 28 mm, 8 Ohm, 1,5W speaker which I put back in place using some black silicon.
I had to swap the old cable and connector to the new speaker by soldering (green circles).