I have just bought a 2003 Volvo V40. There seems to be 3 bulbs behind each knob of the a/c unit and 2 are blown. I got as far as getting the fascia off and i think i can see where the bulbs go but not sure. The unit that pulls out is a white box and the bulbs are enclosed in it somehow. It looks like I need a special tool (like an allen key) to get inside but not sure of the next step. I have photos to make the explanation of the problem simpler but not sure how to upload to this forum?