Once you've registered for a race you can update certain things like your shirt size, answers to registration questions, registration add-ons, etc. by visiting your RunSignUp profile and selecting Manage Registration under the race you'd like to update. Some items have deadlines where updates can no longer be made. Once a deadline has passed you cannot change that section of your registration.
To update your registration follow the steps below after logging in to you RunSignUp account.
Step 1. Click PROFILE at the top of the page.
Step 2. Once on your profile you will see your personal information at the top of the page, as well as any upcoming races you are registered for below.
Step 3. Find the race you are looking to change and click MANAGE REGISTRATION.
After you've clicked Manage Registration you can see all the options available to manage in the menu bar at the top of the page. If an option is not available, the deadline for changing/updating that option has passed.