Sure, it'd be hard to tell you exactly how to replace it though.

If you drive the car at night, as you move the shifter through the gears, the shifter lights illuminate to show what gear you're in, right?
The range recognition switch is the part that actually has those LED's that light up the gear you're in. So in other words, it's inside the shifter assembly, just below the black piece that has the "PRND21" on it (or 321, or whatever it has).
You need to remove the center console, which is fairly easy, and then just 4 screws actually hold the shifter to the floor, plus some wire connectors and the cable for the shift interlock, and you can also disconnect the shift rod from inside the car as well, make sure you set the parking brake though.
But what about the hard code for the control unit?

Gilly