Click Forgot your password on the login page
Enter your e-mail address, then click Send verification code to receive an e-mail with a one-time verification code
Type in the verification code from the e-mail, then click Verify code
Choose and confirm a new password
You can also change your password once signed in, by clicking on your name in the top of the page. Then click Change Password.
This will take you through the same steps as above to provide a verification code that will allow you to choose a new password.