He found a wooden stick and practiced for a few days according to the book's instructions. Once he felt he was getting somewhere, he went to the docks and asked Sylvanas to help him test it. After seven or eight attempts, he finally succeeded once.
Sure enough, a pale golden chain of magical light appeared between Sylvanas's feet, making it extremely awkward for her to walk. But she was a major boss, after all. Not only was his success rate with Lacerate abysmally low against her, even when it worked, she could break the magical chain with a forceful tug, making it vanish.
That was already enough to delight Yu Lin Bloodhawk. He continued searching the two books for skills related to the Hunter class. He spent ages poring over them, every bit as earnest as he had been while preparing for his college entrance exams in his final year of high school.
His hard work finally paid off, and he found two: the intermediate skill Disengage and the advanced skill Explosive Shot. Apart from those two, he could find no other skills.
He guessed it might be because the Hunter class did not exist yet, so many of its skills had not been developed. Or perhaps it was because these two books were Ranger training manuals, and all their skills concerned the Rangers themselves. He had not seen a single beast-related skill. Perhaps things were exactly the opposite among the Night Elves, since they were more proficient in beast training, nature magic, and shooting skills.
The woods around Sunsail Archorage were small, and there were too many people around for him to practice shooting conveniently. Taking advantage of Sylvanas's presence in Sunsail Archorage, he shamelessly pestered her to be his sparring partner. Sylvanas did not refuse.
So he practiced