Revaluation Journal- Forex account balance and Asset Account balance needs to be nullified

Summary:

An incorrect revaluation journal was posted in Nov-19 to the unrealised Forex and Asset account, during Data migration, while conversion from AUD to USD. which needs to be nullified now. On generating the revaluation, the balance is created in Unrealised Forex account. And it's reversed in the next period. On running Revaluation there arises a balance in Unrealised Forex Account and on reversal the balances arises in the asset account and Unrealised forex account balance becomes 0. With what entry can the asset account balance be brought to nil? As per the client requirement these 2 account balances have to