Remove the 2 anti-static bridges using a 15W-25W soldering iron and desoldering braid.
Remove the 4 screws using a Philips screwdriver and remove the top cover.
Open the tray by moving the slide to the right...somewhat firmly, not roughly. Remove the bottom cover.
Using your thumb and forefinger, remove the cable from the laser. It may help to gently apply force alternating at one end then the other. Next, gently open the 2 slide locks as pointed in the picture. Lastly and very gently, free the wires all along the side wall. The circuit board can now be flipped toward the front of the drive.
At the base of the housing on the lower left, turn the dial lock so it's pointing at roughly 7 o'clock.
Move the rail down so the laser can be freed. Swap over the plastic guide and reverse the above procedure to install your replacement laser.