To make any changes to a work schedule that has already been set up, click on repeating on the left side of your work header or you can pick from any piece of work in that schedule. From the options menu (...), select Edit schedule. Or, you can click on the repeating details in the work header.
Either of these options will open a Repeat work schedule box that will let you due dates, work assignee, and other work details.
You cannot change how often the work item will recur; however, you can delete the schedule by selecting "Delete repeat" and starting over. Before doing this, we recommend reviewing the details around deleting a work schedule.