1.  Add a Bank Adjustment to correct the beginning balance of the Bank Account

OR

1.  Create and post a reversing entry in the General Ledger to reverse the amount of the beginning balance out of the cash account with the 'Create bank adjustments when posting to a bank's cash account' box unmarked on the batch.
2.  Create and post a new entry in the General Ledger to enter the amount of the beginning balance into the cash account with the 'Create bank adjustments when posting to a bank's cash account' box marked on the batch.