Open the relevant domain in your My services (Deployment Console) and choose DNS. Review the existing record and the details supplied by the service you are connecting before submitting a change. Keep a copy of the previous value.
DNS controls are available only where the console manages the authoritative DNS service and your role allows editing. If DNS is hosted elsewhere, changes must be made with that provider. Ask us before changing nameservers or mail records if you are unsure: a change can affect your website and email. Cached records may take time to update.