The simplest thing to do is disassemble another tape (a blank one, for example) and compare them side by side. After removing the screws, always turn the tape back over and lift off the side that has the observation windows and the hinge. lways The pieces that fall out are typically the cylinders (metal and plastic) over which the tape rides, the cams and springs that stop the tape from winding unless the center release is depressed, and sometimes the side hinge release.
Hilary Caws-Elwitt, November 2006