As the owner, all you have to do is invite that email address to become manager through the settings in the GMB dash. They will get an email with the invitation to become manager. All they will have to do is accept it and then they will be able to access the GMB dash using their own login info.
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.