There are many reasons why you need to delete personal files and data on your Apple computer or laptop. Fortunately, it's not too difficult to delete everything on a Mac machine. This guide will tell you all the steps. Plus, you can learn more methods to safely and completely get rid of personal files on Mac. The first thing you should do is definitely back up your Mac, as one of the next steps is to wipe the drive completely, so you'll lose all your data.

How to Delete Everything on Mac?

Before deleting everything on your Mac, it's better to back up your computer to a cloud storage or external drive. This is the starting point of every action. In addition, the procedure includes several stages and we will explain them below. You can find yourself in a situation where you need to delete your Mac very easily. 

Sign Out of All Accounts.

Deauthorize iTunes : Open iTunes, go to the Account menu, choose Authorization, and then Deauthorize This Computer. When prompted, enter your Apple ID password and click Deauthorize.

Sign out of iCloud : Go to the Apple menu, select System Settings , and then iCloud. Uncheck Find My Mac, Click the Sign Out button, deselect all options in the pop-up dialog box, and click Continue. This will delete iCloud data from your Mac.

Sign out Music, TV, and Books apps : Launch any of these apps, go to the Account menu, select Authorizations, and select Deauthorize this PC. Enter your Apple ID and password and press Deauthorize.

Sign out of iMessage : Open the Messages app, go to the Messages menu, select Settings, tap the iMessage tab, and tap Sign In.

How to Factory Reset your Mac?

If you are completely sure that you have everything important backed up on the disk, you can start erasing the disk. 

First, on your Mac, click  in the upper-left corner.

Once done, select System Preferences from the menu…

This will open a new window with all sections for managing system preferences.

Ignore the new window, instead click on System Preferences in the top bar on the left.

In the menu that appears, locate and tap Wipe data and settings.

Then a new window will open, in which you must enter the administrator password.

A wizard for deleting data and resetting settings will then appear .

You only need to "bite your way" through this guide until the end, which will completely erase your Mac.

Turn off FileVault : Open the System Preferences dialog and go to Security & Privacy. Go to FileVault, click on the Lock tab and enter the administrator account password. Next, click on Turn off FileVault.

Unpair with Bluetooth devices: if you are using any paired Bluetooth devices, it is advisable to unpair them. You do this by selecting the Apple menu, then System Preferences, and clicking Bluetooth. Hover over the device you want to unpair and click the remove button (x) next to the device name. When prompted for confirmation, click the Delete button.

Reset NVRAM : Resetting NVRAM erases user settings and restores certain security features that may have been changed. To reset this memory, just turn off your Mac, and immediately after turning it on, press and hold these four keys: Option+Command+P+ R . After about 20 seconds you can release the keys. 

Wipe the hard drive and reinstall macOS  – The final step to factory reset your Mac is to wipe the hard drive and reinstall macOS.

Final Words:

When the macOS installation is complete, the Mac will restart and a Welcome screen will appear asking you to select a country or region. If you want to leave your Mac in its factory state, don't proceed with system setup.