We can undo a reconciled statement by manually unreconciling each transaction. I'd be glad to guide you with the steps:

1. Go to the Gear icon and select Chart of Accounts.
2. Find the appropriate bank, then click View register.
3. Select the transaction to edit.
4. Under the Check column, click the box repeatedly to change the status. ("C" - Cleared, "R" - Reconciled, and "Blank" - Not cleared or reconciled)
5. Click Save.

You can learn more information on how to undo from reconciliation in this article: Undo and remove transactions from reconciliations in QuickBooks Online.

If you want hands-on help, you can get a QuickBooks-certified bookkeeper to show you how to do reconciliations and other tasks, check out QuickBooks Live.

You may also consider looking for an accountant to Redo the reconciliation process.

Here's how to invite an accountant:

1. Click on the Gear Icon > Manage Users.
2. Go to the Accountants section and click Invite Accountant.
3. They will be asked to create a user ID before signing for the first time unless they already have an account with Intuit Business Services.
4. Until your accountant signs in, their status on the Manage Users page is "Invited." After accepting the invitation, their status changes to "Active."
5. Click Next and Finish.

You can also refer to this article for the detailed steps: How to invite your accountant to QuickBooks.

Let us know if you have additional concerns, we're here to help.