Did you forget something, what car!!!

On a 90 Old Ciera it's pretty easy.  Go to Autozone and borrow their
special socket and wrench it out.  On other cars it's in a bad spot and
hard to get to.  If you've had overheating problems, it may be very
hard to get off, but usually you can crank it out ok.. Be very careful
installing the new one not to crossthread it or twist the wires too
much.  Also, be careful not to get it cockeyed in the socket and crack
the insulator.  Should be a pretty easy.

Joseph