Do I need to buy both left and right, or can I replace just one side?

You can buy just the right side — left and right are sold separately. If you're matching a damaged unit, grab whichever side you need.

Will this bolt straight onto my vehicle, or do I need any special brackets or hardware?

This assembly uses factory mounting points, so mounting hardware specific to your vehicle should already be in place. Test-fit first to confirm any fasteners need replacing.

Do I need to remove and reinstall the bulb, or does it come with one?

Bulbs are not included — you'll transfer your existing bulb from the old headlight or source a replacement separately. Installation is straightforward once the assembly is mounted.