You should always ensure the personal information held by Sky on you is accurate and change this if things change.
You can change the email used for transactions by going to the Subscriptions tab on the app and accessing the personal details. Add another email address and then update this as the primary one. However, it doesn’t change other communications from Sky so visit the Profile section on the website to alter this.
Never share your password with anyone else as they will have access to your account and be able to order services that you will be required to pay for.