SQL Server/T-SQL Tutorial/System Functions/sp DropRoleMember

A statement that removes a user from a database role

EXEC sp_DropRoleMember db_owner, JohnDoe

Statements that delete the new role

EXEC sp_DropRoleMember BillingEntry, JohnDoe
EXEC sp_DropRoleMember BillingEntry, [Accounting\JaneSmith]
EXEC sp_DropRole BillingEntry

The syntax for sp_DropRoleMember

sp_DropRoleMember [@rolename = ] "database_role_name",
                  [@membername = ] "security_account"