To update the information on an item you have listed on Half.com, you can follow a straightforward process. First, log in to your account using your username and password. Once logged in, navigate to the "My Listings" section where you can find all your active listings. Locate the specific item you wish to update and look for an option labeled "Edit" or similar. Clicking on this option will allow you to make changes to various details such as the title, description, price, shipping options, and any other pertinent information. After making your desired updates, be sure to save the changes to ensure that the new information is applied. If you encounter any issues during this process, it is helpful to check the current webpage for additional guidance or support resources.