Assuming you have just an inflamed tendon, take a few weeks off from direct triceps work. Take 1000mg of Glucosamine twice per day for two weeks and then reduce it as you have less pain.
After the two weeks start triceps work again with high reps and use exercises that you have not done before. Basically exercises that put a different angle of tension on the joint. You may have to stick with this for months until it heals.
This is what I did and it worked for me.
If you are having sharp pain you should see an Orthopedic Physician to rule out ligament tears, etc.