You can manually
convert OST to PST but This process takes lots of time and you may face lots of difficulties so here I am suggesting you professional’s recommended OST to PST Converter. This tool gives single step solution to convert OST files into PST format. The software have unique user-friendly interface which smoothly convert OST to PST files without any risk. This utility also facilitate users to convert selective OST files into PST format. The software runs on all versions of Windows OS and supportable to all editions of Microsoft Outlook.
for more details:
https://www.emailsguru.com/ost/pst/
