2008 Impala shifter is stuck in park and we cannot move the car. Please help.

no power - charge the battery

key stuck - foot on brake, rack the shifter though everything and back to Park.

That is a safety item. look in user manual and you will see procedure.

The shifter is likely broken. Contact the dealer, tell them what is wrong, they can sell you the parts so you can change them, or you might want to call a tow truck to bring the car in for repair.

Do you have brake lights? The brake switch on the pedal has to work to send a signal to a solenoid at the shifter to release park.

Check that the brake sensor is alright. Try putting a new one in at the pedal if you don't have a test light or continuity meter to test it. If the brake being applied is not being sensed by the computer, then it will not allow the shifter to unlock. Possible solenoid problem with shifter, as well, if the brake sensor checks out ok.

The most commonly diagnosed component is the shifter and/or shifter solenoid on your Impala.
GM issued a bulletin on this problem. Contact your dealer, they are aware of the problem and you could be covered under warranty. Below is a copy of the bulletin.

#08-07-30-007A: EI08045 - Key Cannot be Removed from Ignition with Gear Selector in Park, Shifter Cannot be Moved From Park Position (Engineering Information) - (Apr 8, 2008)

Subject: EI08045 -- Key Cannot Be Removed from Ignition with Gear Selector in Park, Shifter Cannot Be Moved From Park Position (Engineering Information)

Models: 2007-2008 Chevrolet Impala
Good luck, i hope this helps.

try rocking the car by hand the gears are locked

This happened to mine. I took the cover off where the shifter is; there is a very small wire that came out on mine, the funny thing is it would only happen once in a while, then one day it wouldn't come out of park at all, that's when I found the wire.

Does the shifter move? If so you may have a broken park actuating rod which requires the skills of a transmission shop to repair. If the shifter does not move then the shift cable or transmission linkage is faulty.

When you turn ignition on it releases a cable that is attached to the shifter also the shifter has a solenoid attached to it that is released when you step on the brake. Both times that I had the problem of button stuck and cant shift out of park the solenoid was sticking and wouldnt release .