I would like to reopen my patent that was closed due to nonpayment of maintenance fees. Should I refile?
No, do not refile
it is not "closed" it is expired. There is a way to ask the USPTO to excuse the late payment and put the patent back into effect. It requires a petition any payment of the fees - and fast action.
From the MPEP
a) The Director may accept the payment of any maintenance fee due on a patent after expiration of the patent if, upon petition, the delay in payment of the maintenance fee is shown to the satisfaction of the Director to have been unintentional. If the Director accepts payment of the maintenance fee upon petition, the patent shall be considered as not having expired, but will be subject to the conditions set forth in 35 U.S.C. 41(c)(2).