The correct way to remove rust is to remove it by the least abrasive means possible.
A wire brush and some light grinding should do the trick be careful not to go to deep with the grinder so you don't compromise the integrity of the component your working on.
Then protect the bare metal with something like POR-15 or a quality rest preventative paint. Regular spray paint will just mask the problem.
The cancer will return if you don't properly protect against it.