When I used to work for someone else they would just call the person or persons in on Friday about ten minutes before quitting time and tell them you're done and escort them out the door. They did pay them off in full at that time.
If it was a manager they would change the locks on the building. You could always tell if a manager was getting the sack when you saw the locksmith arrive.
I was one of only three people that left without being fired, one person had a heart attack and died on the job, second got a new job and never came back, and I told them to stick their job where the sun don't shine and have never been happier.