A big heavy screwdriver works for me, if you can't get it in between the cap and the wheel use a hammer to bray it home.......
Each centre cap will have a small hole (on the chrome ring if I remember rightly) which you hook into to pull them off. Chances are you won't have the proper tool so do what I did, bend some stiff wire to 90 degrees and create your own
__________________
Audi D3 S8 - 2007 - V10. B&O, Phantom Black, black and silver interior, and still completely standard with everything working as it should
Audi TT - 2015 - Ultra