Script to find database users with db_owner role
Select the db in SSMS
SELECT members.name as 'members_name', roles.name as 'roles_name',roles.type_desc as 'roles_desc',members.type_desc as 'members_desc' FROM sys.database_role_members rolemem INNER JOIN sys.database_principals roles ON rolemem.role_principal_id = roles.principal_id INNER JOIN sys.database_principals members ON rolemem.member_principal_id = members.principal_id where roles.name = 'db_owner' ORDER BY members.name