So I got an Audi A6 2007 year version and for some reason one of the buttons on the central console is stuck. It won't pop up anymore like the others. The button I'm talking about is one of the buttons that surrounds the round ****.

My question would be how do I fix it. Do I have to remove the whole deal or just try to life the button with a knife i.e.? Or should I get it fixed in Audi service?

Here's a picture of what it looks.

 

Try to spray first some Electronic Cleaner in the openings (is pretty safe) via the straw - the CRC brand comes with one taped on the can- and see if that provides the necessary "lubrication" to free it. Or you can use rubbing alcohol.
If that doesn't help, it looks like you need to pull out that entire silver-gray moulding. You should be able to pop it from one of the corners. Usually these covers have a hidden recess in the material somewhere along the edge, where you can insert a slim trim tool. Good luck