Apple Macintosh 6500 - Manual (Page 206)

7 Reinsert the screw into the PCI card fence and tighten it.
To help insert the screw, push the PCI card fence forward with your thumb
so the screw holes align. Insert the screw until it’s somewhat steady, hold
your thumb underneath it (to prevent it from falling), and tighten it with
the screwdriver.
You may find it helpful to
support the screw with the
thumb of your other hand.
206 Appendix B