The PCB is also stuck down with thermal compound and may be difficult to break lose. Heating the back of the main housing might help soften this material.

Try to remove by pulling on the edge of the PCB near the connectors.

As a last resort you can try pushing the PCB free by threading an M5 screw into the service port on the back of the light until it pushes on the PCB.

Using a plastic screw, plastic tipped screw or sticking a small piece of plastic to the tip of a metal screw will prevent scratching the PCB.