how to paint wheels?

Hi Guys,

I recently bought a JGTC NSX model, and with it, i'm supposed to paint the rims royal blue, with a silver trim on the outside. From the Tamiya instructions, it says that i should use x-3 paint in a bottle. Well i dont have an airbrush, so my question is:

what steps/how can i brush paint this blue colour onto the rim without ruinning the silver lining trim? i couldn't find a tutorial anywhere :(

Thanks!