It takes practice. Please practice with an old tip that no one cares about.

Only loosen the middle screw. Do not take out the screw completely (it is easy to loose). Be gentle with the screw. It is a standard right-handed screw (clockwise will tighten). Don't over tighten. It should be just tight enough so the tip doesn't fall out. When loosening/tightening, make sure the Phillips screw driver is fully seated in the head of the screw to avoid striping the head.

The two images below show a tip that is pushed too far underneath the clamp, and a tip that isn't pushed far enough under the clamp. In these configurations, it took a drive amplitude of > 300 mV to get the tip to oscillate with 1 V amplitude. Moreover, the oscillation amplitude drifted by > 10% over a 10-minute time scale.

The image below shows a top-down view of a tip that is mounted correctly. It's a little crooked, but it still works fine. When this cantilever was tuned, the drive amplitude was less than 100 mV and the oscillation amplitude remained stable over the 10-minute time scale.

The image below shows a side-on view of a tip that is mounted correctly. The purple line (aligned with the tip) is parallel with the blue line (aligned with glass window).