Radio Shack MICRO-36 - Manual (Page 15)

15 Tape Tips
ERASING A CASSETTE
If you no longer want a recording, you can
record over it or erase it.
To record over a cassette, be sure the
erase-protection tabs are in place. Then
simply record as usual. The recorder
records over the previous recording.
You might prefer to use a bulk tape eraser
which erases both sides of a tape in just a
few seconds.