Find a good book with the text of the hexagrams. Preferably, choose a book with the original poems. The translations are many, and not always happy. I endeavoured to give an at the same time new and respectful interpretation of each one of them. A long time, I believed that the distance of my culture compared to the Chinese origin of Yi-King would be definitively opposed to any velleity major comprehension. After ten years of improvement, I am persuaded that I was wrong. The principles with work are universal. Once seen, they clarify these strange esoteric counting rhymes.
The Judgements, the Lines and the Comments do not have to be even learned by heart so much their logic from construction is beautiful.
Felt once this logic, you will be able to draw Yi-King mentally and to interpret it without recourse to any text! Let us not place the bar too high however.