1. View the subsite in a browser. In the top right-hand corner, click the Gear icon, then select Site settings.
2. Click Title, description, and logo.
3. Change the Title. If desired, you can also change the URL name.
4. After you click OK, you may receive the following error page. The change took effect. It’s a bug where it’s trying to use the old URL that you changed. You can use your browser to navigate back to the top-level site, or go directly to the new URL name you specified.
5. If you changed the URL name and the subsite was being displayed on the navigation menu of the parent site, you might need to manually change the link on the parent site navigation. For example, on the parent site, click the EDIT LINKS option at the bottom of the left-hand navigation menu.
6. Click the name of the item you want to change, then click the globe icon next to it to edit it.
7. On the Edit Link dialog, change the Text to display and update the Address for the new subsite name then click OK.
8. Scroll to the bottom of the left-hand navigation and click the Save button.