Select the Mini DV tape that you want to erase.
Disengage the safety tab on the Mini DV tape. The safety tab, which is a small switch on the top of the tape, prevents recording onto the tape if it is engaged. Exact symbols will vary, but the tab will either display an icon of a lock or a color to signal engagement. Switch the tab away from this symbol to disengage.
Insert the tape into the camcorder.
Rewind your Mini DV tape to the beginning of the recording.
Put the lens cap on the camcorder. Either disable the camera's microphone or place the camera in a quiet place.
Black out the tape. Press the record button in the camera and record until the end of the tape.
Rewind the Mini DV tape to the beginning. Record your new material.