If you know how can do it, please PM.
PM is not necessary. Answer is simple.
If the original transaction is confirmed, then it is too late. Double-spend is not possible for confirmed transactions in Bitcoin OR Bitcoin Cash
If the transaction is NOT confirmed, then you can create a new transaction that spends at least one of the same inputs. Then, you need to hope that the new transaction confirms before the original transaction. You may be able to pay a miner or mining pool to give your second transaction preferential treatment.