Show somebody the door
Definition 1 of 2
Pro Tip 1/3Politeness Varies
The phrase can be polite or blunt depending on your tone and situation. 
The host, with a gentle voice, showed the unruly guest the door.
Pro Tip 2/3Emotional Weight
Saying this can carry a sense of frustration or disapproval toward the person being asked to leave. 
After the argument, he was shown the door.
Pro Tip 3/3Not Literal
The phrase doesn't always mean literally walking someone to a door; it's more about the action of making someone leave. 
She made a scene, so I showed her the door.