How do I petition the courts to remove a co-executor on a family estate? Is an attorney required?

Family estate with only small amount of cash with two co-executors and six beneficiaries. 5 of 6 beneficiaries want to simply file required documentation including tax return to distribute remaining funds according to the will. One of the executors has completed all required steps, the second has done nothing but is required to sign paperwork to release bank accounts and open estate bank account to allow payouts. The "do nothing" co-executor has been asked to make any grievances known that are causing refusal to sign documents. Only says she is hiring an attorney but months go by without action. We are 18 months post DOD and PA Dept of Rev says submit tax return or risk estate seizure. Everything is WELL documented. Can I petition Orphans Court or is counsel representation required?