You could always talk to your local dealers who typically know someone that does wheel repair. At first thought this didn't sound good me, but I saw in person a E46 3-Series 17'' sport wheel redone and one of the Sales Managers 911 wheels repaired too and they both looked awesome.

They told me he couldn't do that sort of "hyper-chrome" finish on E46 M3 19's but after a few months called me back and said he had figured that out too and they had one done to show me. I still haven't had mine done, but like I said I did see two in person that looked flawless. Depending on your damage, this may be the bext route since you're unsure how to replace the wheel. Obviously I'm in Jersey so I can't get you a name but if you try a few local dealers I'm sure they'll have someone for you.

Good Luck!