Do I need to remove the lug nuts to install this cap?

No. The cap snaps onto the factory wheel hub centering without touching lug hardware. Snap it on after the wheel is mounted.

Will this cap fit both front wheels or just one?

This is a single cap. Order 2 if you need both front wheels covered, or order the quantity that matches your setup.

Can I paint or refinish this cap?

The cap arrives as-is. If you want a custom finish, test adhesion on a small area first — material accepts standard automotive paint prep methods.