A common problem with cassette desks is stuck or jammed cassette tapes. In most cases, this is a mechanical issue with the cassette deck, which causes the tape to get caught in the tape deck. There are a few tried and true methods to remove your jammed cassette tapes.
Insert a thin, flathead screwdriver beneath the cassette tape inside the deck. Gently pry upward on the tape until it comes free from the tape deck's heads. Grasp the tape with a pair of needle-nosed pliers. Pull the cassette out of the deck.
Lift the tape out of the deck slightly and untangle the tape from tracking mechanism inside the tape deck. This method only applies to tapes that are tangled up inside the cassette deck.
Grasp the cassette with a pair of needle-nosed pliers, and gently rock the cassette back and forth until the cassette disengages from the tape deck's heads.
Loosen the Phillips-head screws on the outside of the tape deck's casing. Remove the cassette deck's housing until the stuck cassette tape head is revealed. Pull the cassette tape out of the deck.