I'm not sure with the steering wheel controls.
I know that the looms are often present for lights and speakers, but I don't know if that's the case here.
If you're able to get the wiring along with the new wheel hopefully you'll be able to get it working, or be able to tell that the wiring you need is already there, if that makes sense.
@
Guy has his own site, dedicated to the k12
www.micrak12.com
Click on the very last full stop of the introduction to download the pdf manual. Might come in handy
Take care switching the wheels over, due to the airbag.
When you reconnect the battery you will find you'll need a radio code. Unless of course you already have an aftermarket system ^_^
Good luck
Let us know how you get on