Remove the four remaining gearbox screws with a 2mm hex driver.

Hold down the cylinder with your thumb while prying the gearbox apart from the top.

As you remove the right half of the gearbox, be sure to hold down the cylinder, piston, and spring assembly so that they do not pop out under tension.

Also keep a close eye out for any gear shims that may dislodge themselves as you are taking the gearbox apart.