Remove four screws. Three at the swivel point, and one for the clip. Everything should come loose.
Here’s what it looks like after it is uninstalled (just ignore the dangling map lights in the second picture).
Installation
Step 1
Line up the arrow. On the top side of the triangular plastic mount, there is an arrow. The arrow should point toward the front of the car.
Also, each triangular mount is identified with the side of the car it goes to: LH = driver’s side RH = passenger side.
Step 2
Install four screws. All four screws are the same. Three go in the triangular mounting point, the fourth goes into the clip for the other end of the visor.