“How do you treat a slipped rib at home?”

This needs an evaluation to determine exactly what you have and how to treat.

When people speak of a "slipped rib" they are usually speaking of strained muscles of their mid back. If trauma is the cause of your pain and /or causing difficulty breathing you should seek medical attention and be evaluated.
If it is a strain causing your pain, you can stretch at home. Two stretches a recommend can be done with a door frame. First square up to the door frame on the left and put your hands left over right gripping the door frame and lean back to stretch your upper back. Do this for 10 seconds and repeat on the right with right hand over left this time. Second is to compliment this stretch by stretching your chest by putting both hands on either side of the frame and leaning forward, holding for 10 seconds. Repeat 3 times. Repeat sequence 3-4 times per day.
If pain persists seek a chiropractor or MD for further evaluation.

A slipped rib is not a medically accepted diagnosis, therefore there is no treatment for it. I would advise seeking a physical examination for An accurate diagnosis and treatment options.

They can be difficult, but try rolling on a foam roller up and down your back. Often times you’ll feel them ‘pop’ back into place. I really like extension exercises to help as well (rows, face pulls, pull downs).

Ribs can be tricky to get back into place. Deep belly breathing is a good way to expand the ribs and stretch the muscles between the ribs. This, along with thoracic movements may allow the rib to align itself. If this is not achievable, consult a Chiropractor.