Battery in a Nikon D90 stuck?

I borrowed the camera from my college, and went to take the battery out to charge it today and it won't come out? I wasn't the one who put it in, and so I don't know how it was put in. Does anyone know how to get it out safely?

Take it to a proper camera shop. They will know how to extract the battery.

My guess is that you did not get a copy of the user manual when you checked out the camera. Had this happened when you schools' camera tech was still working, they would have been the first choice for help.

OK… Get some double-sided tape (two thicknesses) and attach something to act as a hand-grip. Now you can waggle the battery about and ease it back out. Check that it is the correct battery for the D90 and that it isn't deformed in any way before attempting to put it back in.

Have someone at the college deal with it so that
you can't be blamed for damaging the camera
in an effort to remove the battery.

Bring it back to your college and let them take it out.

If I were you, I'd return the camera back.

The battery may reach its age. Thus it's swollen that you can't remove it easily. Charging or continue using it may cause damage to the battery or the camera.

No need to take the responsibility for the already-damage borrowed equipment.