I migrated my data to QuickBooks Online from Quickbooks Desktop too soon, and want to reinstall.

Purge your QBO account and re-convert your data from QB Desktop. If your QBO account > 60 days old, cancel it and signup for a new one instead.

Thank you! I got most of the way through the process (at the Wipe Data command) and keep getting a "504 Gateway Time-Out" message. Any thoughts on a work around? Thanks!

It's nice to see you here in the Community, @GlennC45.

Let me chime in and provide information about migrating your data in QuickBooks Online(QBO).

To start, you can convert your QuickBooks Desktop (QBDT) file to QuickBooks Online (QBO) by overwriting the existing company in QBO with your updated QBDT file, as long as your books are less than 60 days old.

Also, as 4GAL mentioned, If it's been over 60 days, you may consider subscribing to a new QBO plan, then cancel your old plan since it's only 60 days you can migrate your data.

If you want to delete your canceled company permanently, find out more about this process by checking out this article: Access and manage your data from your Intuit Account.

Let me know if you need further help in managing your data or other QBO-related concerns. I'll be here to assist you.