How to save existing company file then reset opening balances as of the first of this year?

Thanks for reaching out to us, jdrosenlof5366.

If you're using the QuickBooks Online Advanced plan, you can check out these articles on how to back up your data: 

• Back up and restore your QuickBooks Online Advanced company (formerly ChronoBooks).
• Announcement: ChronoBooks backups only available for QuickBooks Online Advanced

For QuickBooks Online Simple Start, Essentials and Plus, you'll want to manually export the data by following these steps:

1. Go to the Gear > Export data.
2. Select the Reports or Lists you wish to save.
3. Click Export to Excel.

Here's an article for reference: Export Data out of QuickBooks Online.

You can also go to the App Center by clicking Apps on the left panel, and look for a third-party app that has similar function. 

With regard to the opening balance, you'll want to manually edit the transaction.

Here's how:

1. On the left panel, click Accounting > Chart of Accounts.
2. Click the View register link of the account you want to view.
3. Find and select the opening balance entry. You can use the Date column to sort the transactions from newest to oldest, the opening balance entry may be at the end of the list.
4. Edit the amount. Tip: If you're not able to edit the amount directly on this screen, in some cases you can click the Edit icon.
5. Select Save. 

I'm adding this link for more details: Edit an incorrect opening balance.

Please let me know if there's anything else you need. I'll be around to help you some more. 

@Anonymous 

You don't need to export or reset anything but edit the opening balance. Do you have any other concern?