Use a slant board with 15-30 degrees, the higher the better. Lower to no more than 60 degrees flexion at the knee using a 3 second count down and a 3 second count up.

Use enough weight to cause pain in the tendon. On a scale of 0 - 10, 0 being no pain, 10 being terrible pain, choose a weight that causes a 3 or 4 intensity of pain for the number of reps. If a weight no longer hurts, increase it.

Week 1 - 3 sets of 15 reps
Weeks 2/3 - 3 sets of 12 reps
Weeks 4/5 - 3 sets of 10 reps
Weeks 6-8 - 3 sets of 8 reps
Weeks 9-12 - 3 sets of 6 reps

Try to perform 3 sets everyday for the full 12 weeks. If you miss a day here and there, it’s fine. Just do at least 3/5 days a week.

Slant Board http://amzn.to/2yaT38O
Foam Rolling https://overhaultraining.vhx.tv/videos/general-foam-rolling
PNF Quad Stretch https://overhaultraining.vhx.tv/videos/pnf-quad-stretch
Forum Thread https://overhaultraining.vhx.tv/forums/general/19385-patellar-tendonitis-recovery-program

WHY ARE ECCENTRIC EXERCISES EFFECTIVE FOR ACHILLES TENDINOPATHY?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4527202/

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1724276/

Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy. https://www.ncbi.nlm.nih.gov/pubmed/19793213

Superior results with eccentric compared to concentric quadriceps training in patients with jumper's knee: a prospective randomised study https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1725058/

Eccentric decline squat protocol offers superior results at 12 months compared with traditional eccentric protocol for patellar tendinopathy in volleyball players http://bjsm.bmj.com/content/39/2/102

Heavy Slow Resistance Versus Eccentric Training as Treatment for Achilles Tendinopathy http://journals.sagepub.com/doi/abs/10.1177/0363546515584760?journalCode=ajsb