What should I do with a book I borrowed from school in my childhood and haven't returned yet, and it's a bit torn?

What has been borrowed must be returned to its owners, due to the Sharia's command regarding the obligation of fulfilling trusts, as the Prophet, peace and blessings be upon him, said: "(The hand is responsible for what it takes until it returns it)." This is also due to what ethics necessitate regarding the preservation of trusts and the return of rights to their rightful owners, and because the failure to return borrowed items corrupts dealings between people and creates chaos. Furthermore, not returning borrowed items causes distress and harm to their owner, for trustworthiness is a great principle among the foundations of coexistence among human beings.