With a snap.
Another thread of causality was cut off.
It was Link's gain after he figured out the origin of Death Valley, his connection to Death Valley, and even this world.
It had nothing to do with the deal he agreed on with Lorin Ben.
Thus far, out of the five threads of causality and one lock on the door, two threads of causality had been severed. The progress was encouraging.
Link had achieved insight.
He had made a mistake in his judgement that becoming the top martial artist at the Martial Arts Conference eight years later would complete his trial when he lacked information.
Becoming the new top martial artist would not cut off the threads of causality, nor would it cut off the shackles to open the door.
Based on the experience of the two previously severed threads of causality, Link believed that severing his connection with this world, repaying the favors received, was the key to cutting off the causality and removing the shackles to complete the test.