Launch a web browser, go to qbo.intuit.com then log into your Quick Books Online account (I am using QuickBooks Online Plus).
Enter the following url:
qbo.intuit.com/app/exportqbodatatoqbdt
Request the .qbxml file from Intuit.
Download QuickBooks Desktop Enterprise trial.
Install QB Desktop.
Once the .qbxml file is acquired, import into QBD. You will be prompted to give the resulting .qbw company file a name.
Load the .qbw file. Sign in as an admin to the desktop company file you want to move.
On your keyboard, press Ctrl + 1 or F2 to open the Product Information window.
Press Ctrl + B + Q, then select OK to display the export window.
On the export window, select Get started.
If necessary, sign in as an admin to your QuickBooks Online company.
Select Choose online company, then select the QuickBooks Online company you want to replace with your company file.
Select Continue.
If you get the error about not being able to export to QB Online after 60 days use the support call back option under Help. Ask for migration assistance, the agent will remove the two month limit.