First of all, download OST Export Tool and launch perfectly on your computer desktop. When it gets launched, the screenshot will be appeared as:
Here, you will get three options to add OST file :
Add Files
Add Folder
Load Outlook Profile
If you want to manually select and load OST files, then click on Add File or Add Folder button.
And, if you want to add OST files directly, then you can use Load Outlook Profile options (make sure it is configured)
Choose desired option to load OST file for conversion.
Now, tool will immediately scan the selected OST folder.
All OST items now listed on the software pane with checkboxes. You can select/deselect the checkbox of desired item and move selective files without any issue.
Select desired saving option in which you want to export OST file.