I parked my blazer on a very slight incline, then turned the car off. A few minutes later, I tried to shift it out of park but the shifter level would not move at all. The next day, I was eventually able to get it out of park by playing around with it for a little while and pushing the lever down pretty hard. Got it back to the shop, then messed around with the shifter cable on the lift. Now, it will not go back into park, although I can manually put it in park under the car. Is this the shifter cable? Or something else?

 

The parking pawl can get wedged pretty good when parked on a hill/incline. You probably got it out of adjustment when you pulled on it hard. Swartlik has a post about adjusting the cable if you do a search.