How should i do physical therapy on my knees?

Get instruction: You need to make an appointment with a physical therapist, who can instruct you what exercises and stretches will be helpful.

Cannot answer: Unfortunately i cannot answer that because there are different kinds of physical therapy for different knee conditions. So rehabing someone for a torn acl may be different that rehabing someone for osteoarthritis. Best thing to do is see an orthopedist or physiatrist and they can guide you.