I want to paint them, how should I go about it?What paint is good for that?

 

duplicolor
http://youtube.com/watch?v=z3s4nMR0yxk

 

Duplicolor is good. Make sure you experiment with it on something else first. I screwed my rim up and ended up spending a lot of time sanding it smooth. Make sure you take your time and try not to cake it on.

It will be easier if you have the tires removed. You won't have to worry about masking and you can get a better coating of paint on the lip. If you have a paint run, make sure the paint has cured before you start sanding. It's possible for the sand paper to gum up and actually pull/stretch the coat of paint.

 

Not sure if you are wanting a DIY project, but if you aren't... you might look into getting them powdercoated.

 

If the budget allows it, powdercoating is the way to go for durability.