How to remove a director from pvt. ltd company

Hi all,

        Me and my brother are the share holders of our company. before two years we appointed two directors to our company ( they don't have any shares). with in six months they two formed a company at thier own and now they operating thier company.and also refusing to leave our company too.they had voilated code of conflit of my company policy..please guide me to remove them from my company.