Follow the steps to analyze and delete large files from external storage drive: Step 1:Download and install Disk Usage Analyzer on your Windows computer. Step 2: Connect your external drive and run this Drive Usage Analyzer Tool. Step 3: The program begins scanning your external disk and listing all of the large files there. li>Step 4: Click the Delete button to remove all unwanted large files / folders from your external drive. That's it. This is how you can scan and delete unwanted large files / folders from your external storage device.