There are two distinct management roles in Crowdstack:
The person that initially creates your Crowdstack is an Administrator and is also listed as the "owner". There can only be one owner of a Crowdstack.
You can add, remove, and change status for Administrators and Moderators in your Management Settings. Go to Manage > Settings > Management Roles.
To assign a member a new role or change an existing role, click on Manage this Crowdstack > Settings > Management Roles.
The page looks like this: