Do these mount at the factory rocker points or do I need to drill?

These mount at factory corner locations with no drilling. Existing fastener holes line up — use the hardware already there or bring your own to match.

Are bulbs included with these housings?

Bulbs are not included. You'll need to source replacements that fit the socket type — confirm your bulb spec before ordering.

Do I need to prep or seal these before install?

Black finish is ready to go as-is. Once mounted, check gaps for water intrusion and caulk around seams if needed to keep moisture out of the fender wells.