Stretching is relatively easy but requires dedication. Start with a good warm up and joint rotations. Then hold the specific stretch for about 1 minute each side, shake it out, loosen up with some more rotations and then hold the stretch again for about one minute each side. Repeat again.
When holding a stretch you don't want to feel sharp pains, you want to push into a mild discomfort but not too far. Make sure all your joints a properly aligned. Posture is incredibly important when stretching, avoid hunching.
Hope this helps!