Do I need to remove the door panel completely to install this?

Yes. Full door panel removal is required to access the mounting cavity and disconnect the old assembly. You'll need basic hand tools and patience — take photos before disassembly to remember connector positions.

Will this work if my original motor still runs but the regulator is broken?

This is a paired assembly, so you're replacing both at once. If your motor works fine, that's okay — the new unit gives you a fresh mechanical system and eliminates any wear in the old regulator linkage.

What mounting hardware is required?

The assembly bolts directly to factory door mounting points. Confirm bolt count and size by checking your door cavity before installation — hardware not specified in the assembly specs, so reference your Sentra service manual or test-fit to verify fastener needs.