You can use the following URL to initiate the download in Internet Explorer to export the data: http://qbo.intuit.com/app/exportqbodatatoqbdt. After that, prepare to export your QuickBooks Online data by following the steps below:
Click the Get Started button in the Export Overview window.
Select Install under ActiveX Control Now.
When it's finished, click Continue.
Choose the data you want to export, then click Continue.