Navigate to your profile page by clicking on the profile page and name in the top-right corner of the screen.
You'll see a box on the top of the page with your profile photo, name, and some basic info. In the top-right corner of that box, you'll see a white button labeled "Edit." This will open a pop-up to edit your basic information.
You should see a highlighted blue field for your email address. On the right side of that field is an orange pencil icon with the word "Edit." Click that to change your email. That will open another pop-up, this one entitled "Edit Email."
Submit your new email address. You'll be sent a 6-digit code to this new address to confirm it. Submit that code on the following page to verify the new address.