Good day, @zummo.
We're unable to download payroll data from QuickBooks Online Payroll into QuickBooks Desktop Enterprise. Though, you can export employee information by creating a report and exporting it to Microsoft Excel.
To make your payroll transition easier, you can enter prior payroll instead. Check out this article for more details: Enter historical payroll data.
Also, I've included an article that'll help you enter payments that you've already made for taxes and other payroll liabilities from the beginning of the calendar year: Enter historical tax payments in QuickBooks Desktop Payroll.
You can always get back here if you have additional questions. I'll be around to help.