Once youve adjusted the aim of your projector go ahead and replace the glass covers onto the reflectors, if you are completely done, Jb weld the screw

Are they hard to adjust them?

The problem is its hard to figure out where exactly to drill the holes for the screws. they need to have the correct spacing and also the right angle. Im probably going to lasercut a guide to fit on the back of the lens that will make it easier to get the correct pattern and angle.