How do I renew or recheck a book? You can come by or call the issuing library to renew or recheck a book. You can also renew or recheck books online by logging into your ALCON account. Go to ALCON Library Catalog and click on My Account. If you are not already logged into my.acu you will be prompted to do so. Click on Renew My Materials. Check mark the boxes next to the books you want to renew then click on the Renew Selected Items button.