OneDrive Backup Tool is the most trusted and highly secured utility to migrate OneDrive to another OneDrive and Google Drive account. The utility also featured several advanced features to help OneDrive users to migrate data items from OneDrive accounts. It is capable of migrating and saving all the data and files such as Audio, Video, Files, DOC, DOCX, PDF, etc. They are embedded allowing duplicate files to migrate or backup OneDrive duplicate files. You can download the free demo version of the software to analyze the performance. 

However, if you are looking to convert OneDrive files to an external hard drive then here is an informative article for your OneDrive Files To External Hard Drive. Here you will get the most efficient and effective manual ways to migrate the process.