You can update your Email from the in-game menu. In the "Account" settings there is the option to update your Email.
As for updating the Phone number, the easiest way to do so is to open a new account using your new phone number and contact us at email@example.com
to connect your old account to the new Phone number.
In case you still have difficulties with updating your Email/Phone number, feel free to contact us at firstname.lastname@example.org
and we will make sure to help you.