2001 Mercury Sable Hard to get out of park

Your Transmission is fine. You just need a new brake switch. It's located just above the brake pedal, and looks like a push switch with a circle on one end. They are $12 at Autozone, and are easy to install. Just get under there, take a pictures of how it is installed, pull the green spring clip, slide off the two plastic grommets and disconnect the switch plug. Having the picture of how it went back together, to hold the plunger that pushes into the firewall is nice, so you can reinstall it correctly. Do this, and you should be golden, unless you broke a wire as well leading to the brake switch.