Sit on the floor with your legs comfortably in front of you. Your chest should be up and your back straight. Put your hands on the back of your head and interlace your fingers. This will be your starting position
Have your partner stand behind you and put his/her hands on the inside of your elbows. Allow them to pull back on your elbows until you feel a stretch in your chest and front delts. Hold for 10 seconds.
After 10 seconds, try to bring your elbows in against your partner's resistance. Hold that contraction for 6 seconds.
Now, relax your muscles and have your partner gently pull the elbows back as far as it comfortable for you for 30 seconds. (If you want, try contracting your upper back for greater ROM gains.)