After you remove McKing from the door you find out it is locked with an electronig lock. You can use a magnet to bypass the lock.
You know that electronic motors have magnets in them? ?
There is an electronic motor in the ceiling fan in front of McQueen's office. Click the fan to get the fan motor.
Now pry the magnet out of the motor. You will find a small enough tool.
Look closely the dispatch room. ?
Click the drawers right from the dispatcher.
Use the bobbypin to get the magnet out of the fan motor.