Best way to fix tiny tiny rust spot?

[jtsanders]

I would prime it after removing the rust. After 2 years, the metal is probably pitted. Using a rust converter type primer would transform the rust in the pits to a benign compound and protect the bare metal. Put masking tape around the spot. The tape should be attached to the roof and a few sheets of newspaper. Now you have a spray shield to put the primer on. The primer can be sprayed. Start on the newspaper and sweep over the repaired spot. Don’t stop moving the spray around until the spot is covered. Then top coat with the touch-up paint. I’ve done this before and it works well.