To modify the content of the SharePoint sites follow these steps:
- Download OneDrive app for business from this link.
- Open the root site that you want to modify e.g. Admin site.
- Click on the sub-site that you want to modify or edit, in this example, I will edit the Technology sub-site.
- Click on the Sync link to the Technology sub-site to your local profile.
- After the sync'ing is done, click on Show my Files