Within Gmail, you can edit Yesware Contacts in your Contacts Sidebar. To do so, you'll want to open an email with a Contact or search for a Contact at the top of the sidebar. Once the profile pops up in the sidebar, you can click the pencil icon next to any of the fields to update the information. Once you make the edit, click Enter to save the updated information.
Within the App Site, you can select a specific Contact or search for the Contact you'd like to update. From there, you can click on any information associated with the Contact and click enter to save.