You will be able to change the sharing & permissions through either OneDrive web access or on your desktop OneDrive if you have set it up.
Sharing via OneDrive Web Access
- Login your office 365 account from this link and access your OneDrive.
- Select the folder/file you want to share.
- Click the Share button.
- Ensure that the correct permissions are enabled and click Apply
- Enter the email of the person to share the file and click Send.
Sharing via OneDrive in desktop
- You have to finish setting up OneDrive in desktop. Otherwise follow these steps here to complete the setup.
- Open your OneDrive folder in your PC.
- Select the folder/file to share. (You may only choose either 1 folder or 1 file.)
- Right-Click on selected folder/file and click Share
- Ensure that the correct permissions are enabled and click Apply.
Enter the email of the person to share the file and click Send.