The following 4 exercises will help you soothe the pain in the knees quickly:
You should start in a sitting position. Extend one leg in front of you and elevate it to be parallel to the ground. Hold for a minute, and then bend the knee to lower the leg halfway to the ground. Hold for half a minute, and return to the starting position. Make 4 repetitions, and switch legs.
Half-Kneel Hip and Quad Stretch
Place a mat on the ground, kneel on the right knee, and put the left foot in front of you. Stretch the hip downward by leaning forward to the left knee. Then, lift the back ankle toward the hip to stretch the hamstrings, and switch legs. Make 15 repetitions.
Sit on a chair, with the feet in front of you. Then, take a towel and loop it under the foot while resting on the floor, and pull on the towel slowly until the foot is about 4-5 inches above the ground, and the knee is bent. Switch legs and do 5 repetitions.
Wall Calf Stretch
Lean against a wall, standing, and rest one foot on the wall, and the other on the ground. Lean forward to stretch the calf, and hold for 5-10 seconds, and then release. Change the leg and perform the same 10-15 times.
If you perform some of these exercises on a daily basis, you will effectively treat and prevent knee pain.