Will this fit my truck if I have a running board or other side step already installed?

You'll need to remove any existing aftermarket side step before installing this nerf bar. It mounts to the same factory points, so dual installation isn't possible without modification.

What hardware comes with this, and what do I need to source separately?

The assembly ships as a complete unit. Check the mounting hardware against your truck before final tightening — some buyers prefer upgrading fasteners for added security, but the OEM-grade hardware provided will work.

Can I paint this to match my truck, or does it come finished?

The bar arrives ready to install as-is. If you want a custom color match, light sanding and standard automotive paint will adhere cleanly to the factory finish.