Each Friday Pulse account has a single Account owner. The Account owner is the only user who can update payment details or download invoices.
Only the current Account owner has the ability to make another Admin the Account owner. They can do this by logging in and heading to the People section (via the top menu):
Once the selection has been confirmed, the former Account owner will be automatically have the user type of Admin and the new Account owner will have the standard Account owner access and permissions.