Back to the point, if you want to clear your Mac hard drive thoroughly, the third-party software will help you a lot. What's more, it will save hours of time spent on it. What you need is to choose a powerful cleaning tool such as Apeaksoft Mac Cleaner. As the powerful Mac cleaning and managing tool, Mac Cleaner can help you wipe any junk files, old or large files, mails, photos, uninstall seldom-used apps and more. This program also helps you monitor system performance and keep your Mac in good status.

Step 1. Free Download Mac Cleaner by clicking the download button. Install and launch it on your MacBook. If you want to view your Mac performance, you can click Status to check system status.

Step 2. Click Cleaner and choose one file from the available options. You can select from System Junk, iPhoto Junk, Email Junk, Similar Photo, iTunes Junk. Duplicate Finder, Trash Bin. You can also find large files on your Mac with the help of this software.

Step 3. After scanning by clicking Scan button, you can click View button to preview the scanned files.

Step 4. Check the item you want to delete, and click Clean button. Then confirm your deletion in the pop-up window.

Restore Mac to Factory Settings with Built-in Feature: https://www.apeaksoft.com/mac-cleanup/how-to-wipe-a-mac.html

I've never needed this but just in case I saved your guide