Go to the “My Profile” link in the nav bar. The email you use to log in can be updated from your profile page in the personal details tab.
To update your password, hover over your avatar on the right of the nav bar. Select the change password page.
Enter your old password and then what you would like to change your password to. Confirm your password by typing it in again. Then save your new password by clicking the “update password” button.
Now when you go to log in this updated password will be your new password.
If you have forgotten your password altogether. Click the “forgot password?” link on your login page (section 1). This will send you out an email link to set a new password.