my brother and i are co executors of my fathers will can my brother retain a lawyer and proceed with probate without me

If you do not want to serve as Co-Personal Representative of your father's estate, you can waive your right to priority. Whether your brother will serve by himself or you will be replaced by a Successor Personal Representative depends on what your father's will states. Your brother should seek out a probate attorney to help him carry out his responsibilities as Personal Representative.