Voiding remainder of a split payment?

Does anyone know if there is a way to close/void the remainder of a split payment in AP?  Voucher was created for the full amount (example: $30,000).  Then, split payments were done (twice) to pay $15,000, then $10,000.  The remaining $5,000 is now not to be paid.  AP needs to close/void this remaining amount and not pay it.  Do we have to reverse the other two payments, then reverse the voucher, change the amount, then revoucher/repay?  Or is there a way to void or simply close (like a "9" in receive open orders) that closes out the remaining open voucher amount?

Thank you!!!