I would say initially into the stretch keep it VERY light. This is because otherwise the ligament will 'compensate' with equal resistance in the opposite direction, minimizing the effectiveness of the stretch.
Then once in the stretch for say 20s, modify the stretch in some way...that is - add another angle ala V-stretch or OTW to increase resistance of the stretch even more but gradually. Hold for another 30s-1min.
This is when the stretch is REALLY effective and here is the positive PI:
You will actually feel the penis "give"
---meaning it will 'relax into the stretch'. Breathing deeply through the abdomen helps facilitate this.
Read the science:
Science Regarding stretching
and also this very helpful stretch to coax out the 'inner penis':
Internal Penis Stretching which has been extremely effective for me