Kinda depends on why its stuck.
If the player head is stuck, then you can try using a thin, small screwdriver and push it in (gently) under the cassette and kinda rock it on one side (up down) and then in the middle and then on the other side. If the player head is stuck, sometimes a little encouragement makes the head release.
After you try rocking it (or while you are doing it), you can use either a pair of long nose pliers or a straightened paper clip (bigger is better) with one end kinda in a hook shape. You are trying to grab the cassette case and worry it forward toward the opening.
You may have a tangled tape and it will string out (remaining stuck in the player) OR the tape may pull a little but then release. If the tape breaks, you can use repair tape and fix the break. Most of the tape will remain usable but you'll have a small bit that is static or quiet while it trys to play the tape fix.
Very worst case, you'll need to remove the front plate and get to the guts to pull it out. That would mean you'd need to remove the radio/cassette player from the dash.
I've been lucky enough to get a stuck cd out of the cd player in my dad's truck. It was stuck in there for 5 years cause he was angry at the cd player and refused to let anyone fix it. Once I inherited the truck after his death, my very first thing was to use a screwdriver and gently lever it up to get it out.
The only cassette I got stuck in a player was mangled beyond belief when I finally got it out. Eventually, after playing it about 20 times, it mostly played properly again. And fortunately, the members of Earth, Wind, & Fire never found out how wonky they sounded in my car.
JW
