1) Sand the wheels with 60 grit paper followed by 120 grit paper
. This should removed the majority of the paint.
2) If you've got kerb damage like I did, file or sand the damage down until the lip is circular, then mix up some of the liquid metal and smeer plenty of it on to fill the damage. Let it dry and then sand it down to the same level as the rest of the wheel.
When spraying, spray at a distance of 6inches and spray with a smooth motion and with light coats. If you spray beyond the edges of the wheel then you can avoid getting an excess of paint building up along the rim.
Lots of light coats is much better than 1 heavy coat. If you've put too much paint on (small pools of wet paint) then let it dry and see what it looks like. Don't try and cover it with more paint. If you get a run, let it dry and sand it down with the 800 grit paper.
Always spray the rear of the wheel first, as some paint will overspray onto the front.
3) Spray the entire wheel with a light coat of etching primer, until you can't see any bare metal This is very important with alloy wheels. Once dry Spray several coats of regular grey primer ontop of this. Put plenty of coats of primer on as you will need to sand it back.
4) Once the primer is properly dry rub it down (very lightly) with wet 800 grit paper this will give you a nice smooth finish, try not to sand through the primer. If you do you can always spray some more.
5) Clean the wheel off with a damp cloth and spray several coats of the colour of your choice. I chose black. Again try to avoid putting too much on in one go, and again start by spraying the back.
6) Make sure the paint is dry, spray on several coat of lacquer to finish it off. Spray the coats lightly and evenly as its quite easy to mess this up. Don't put too much on in one go!
7) Let the lacquer dry overnight and t-cut / polish it to a smooth finish.
If you are unable to do it yourself then you can of course use Alloy Wheel Repair specialists.