Pull out the tape from the cassette. Pull until the tape is to the end point on the tape heads (cogwheels).
Insert a ballpoint pen into the right-hand tape head.
Turn the pen counterclockwise while keeping the length of tape from tangling as it is being wound back into the cassette.
Turn the pen until all the tape is back in the cassette. The cassette can now be inserted and played in a cassette player.
Preheat an oven to 130 degrees Fahrenheit.
Place the tape on a baking tray and insert in the oven. Leave for 1 to 2 hours.
Take out the tape and allow to cool. The glue that binds the oxide to the plastic of the tape should be rejoined and improve sound quality.
Gently pull out the tape from the cassette casing with your finger until there is room to place a pen underneath. Place the pen underneath and continue to pull out until you reach the damaged portion of tape.
Cut out the entire section of damaged tape. Cut the tape straight to create a clean join for re-forming.
Cut a small piece of sticky tape or duct tape.
Join the two remaining sections of tape with the sticky tape.The two sections should overlap about a millimeter. Wrap the sticky tape all the way around the two sections, and press them together. Wind the tape back in the cassette using the method in Section 1.