Send a mirror ahead, bounce the beam back toward the ship to push it backwards. Loses a lot of efficiency, though. Laser propulsion, a lot of the thrust is coming from ablation of the surface.

How do you 'send a mirror ahead'? Do you want it to stop, or just keep flying away indefinitely?

Yep, throwaway mirror, it goes off to wherever once it's done bouncing light back at your ship. Again, much less efficient, so when you get where you want to go, you'd want to put in a laser station there too.

Use lasers for the first half of the journey to send a rocket that can decelerate and build the laser station at the destination.