Your best bet is to invest in a full Multi-Function steering wheel and not just the buttons. It is the easiest option. However, you will need to upgrade your steering wheel control module too.
I've gone with the steering wheel option myself and got
@Eddie-NL to fit and code. However, if you are in the London or Nottingham areas then
@RetroRaz will also be able help.
Also, what HU do you have? And do you have the highline display in your car? Both will make the MFSW more useful.