Ligament is the end of muscle, which is less elastic. You should do it bit by bit. If you pull hard, you will never recover naturally unless you spend a lot of money to graft in a special sports hospital.

So don't worry, do it bit by bit, pull it properly before running every day, pull it a little hard after running, and it will open in two months.

This kind of stretching is passive stretching and active stretching, and the effect is better than passive stretching.

I suggest you buy the first and second volumes of Prisoner's Fitness and have a look. They are good for fitness.