Crimson Trace CTS-1500 Installation Guide

I just purchased the CTS-1550 ( the CTS-1500 is no longer available?) to mount on my XDS Mod2 OSP .45; sadly the screws provided were a bit too long to snugly mount the optic to the slide. Waiting to hear back from Crimson Trace to see if they can provide the appropriate sized screws that won't bottom out in the slide.