Note: Versioning is only available for certain file types such as documents and spreadsheets that you have created. If a file has been shared with you, the original owner of that file must follow these steps.
1. Open Office 365 and go to the OneDrive tab OR follow the instructions for "Accessing OneDrive on the Web" here : Accessing OneDrive From the Web
2. Go to "My files" in the left-hand side menu.
3. Right click the desired file and select "Version history".
4. A menu with the version history of the file will appear. Right click on the desired version to open it or restore that version of the file.