Hi Apple890423, welcome to the Ubisoft forums!
If you'd like to hid the game from your library, you can hover over the title in Uplay, click the bottom right arrow, and press "hide" and that will allow you to not see it anymore.
If you'd truly like to revoke the game from your account, please reach out to our team at
https://support.ubi.com by clicking on "Contact Customer Support". Our technical support team can look into this request for you. (Please note that this will take any right to play the game off of your account and you will not be able to play it again without purchasing a new copy. You probably just want to hide the game instead.)