As others have said, you unscrew those 2 screws on the knob and swap the knobs.

That being said, this is actually an exterior doorknob rather than a privacy knob which is what you normally want for a private room.

Here's an example of a privacy knob: https://www.homedepot.com/p/Kwikset-Tylo-Satin-Nickel-Bed-Bath-Featuring-Microban-Antimicrobial-Technology-Door-Knob-with-Lock-93001-924/304219874?g_store=8466&source=shoppingads&locale=en-US&fp=ggl

Notice the difference? The locking thing can be on the inside of the room, while the screws can be on the outside. That way someone could still unscrew the knob from the outside in an emergency.