Stuck In Park

I just bought a 1997 Oldsmobile Cutlass with a 6 cylinder engine. Has only 49,000 miles. It's gear shift is on the console. When I crank it up and try to shift out of park, I cannot get it to move. I depress the brake as the book calls for and try to push in the button on the left of the gear knob, but it is just stuck. I even try to move the steering wheel from side to side with the engine turned on, but to no avail. I try and wiggle the gear shift while trying to push in the button, and only after about 3-4 minutes, it finally engages. Can anyone give me any insight on what to do so I can get on with driving? Is there a way to get into the knob where the button is attached to see if something is wrong? Can you spray some WD-40 into the side of the button to loosen things up? Thanks!