This is not the impression we want you to have when undoing reconciliation, @MichaelAparicio. 

To entirely undo a reconciliation, only accountants who use QuickBooks Online Accountant can perform the process. This is because the software has the necessary tools for an accountant to ensure the recordings are accurate and balanced. 

If you know which transaction you need to change, you can unreconciled an individual transaction from a completed reconciliation.

Here's how:

1. Go to Accounting.
2. Choose the Chart of Accounts tab.
3. Locate the account that has the reconciled transaction and then click View register.
4. Find the transaction. If the transaction is reconciled, you’ll see an R in the checkmark ✔ column.
   
   
5. Click the transaction to expand the view.
6. In the checkmark ✔ column, choose the box with the R until the box is blank. This removes the transaction from the reconciliation.
7. Click Save and close the account register.

For additional information, you may also check out this article: Undo or remove transactions from reconciliations.

Once done, you can redo the reconciliation. This way, your accounts always match your bank and credit card statements.

That should do it! Let me know how it goes by leaving a comment on this thread. I'd be glad to answer if you have any follow-up questions or concerns. Take care and have a good one.