You can update your personal information in two ways:

First, from only on your desktop, you can click on the Quick Actions dropdown tab at the top right corner of your screen and select Personal Information in the drop-down menu.

Second, from your desktop, look to the left-hand side of your screen for the vertical, blue menu and click on Profile. This will take you to a new page where you can edit your personal details.

To access this page from mobile, simply tap on the hamburger menu in the top right corner of your device, and click on Profile from there.