A family of Microsoft products that enable users to capture, organize, and reuse notes electronically.
You can use either the manual copy method or export and import through the OneNote desktop application.
The first method involves copying sections into a new notebook. Open OneNote on your computer and sign in with both your old and new Microsoft accounts by going to File > Account > Add Account. Open the notebook associated with your old account, then create a new notebook under your new account by selecting File > New and choosing the new account's OneDrive. In the old notebook, right-click each section or page, select Move or Copy, choose the new notebook as the destination, and click Copy. Allow the new notebook to fully synchronize with OneDrive before considering the transfer complete.
Alternatively, you can export the entire notebook as a OneNote Package (.onepkg). Open the OneNote desktop application and sign in with your old account. Go to File > Export, select Notebook under Export Current, choose OneNote Package (*.onepkg) as the format, and click Export to save the file locally. Double-click the exported file to unpack and open it on your computer. You can then move or copy its sections into a notebook associated with your new account, or use File > Save a Copy to upload it to the new account's OneDrive.
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hth
Marcin