Now is the time to imagine you are defusing a large bomb! Firmly grip the secondary assembly with all fingers. DO NOT use the knob located in the center of the secondary. This knob is only glued on, and one time it came off on me while performing a switch. I managed to catch the secondary in the other hand, aged ten years, but never touched the mirror surface. Do not trust it! After the secondary is removed, it should immediately be placed in the protective cell furnished with the Fastar optics set.