You can change your password and your email in the Security tab of the user settings. 

You can change your email address at any time by selecting User settings under your profile picture: 

Navigate to the Security tab and enter a new email address. 

Click Save new email. You will receive an email confirming the requested change.

You can change your password at any time by selecting User settings under your profile picture menu.

Navigate to the Security tab. 

Enter you old password and your new password twice. 

Click Save new password.