how to put in tecovery mode on Apple Mac
How reset owner passwode
Press the Command and R keys at the same time when the grey screen appears and hold them until you see the Apple logo. A small loading bar will appear under the logo.
Your system boots into Recovery Mode.
Click the Utilities tab in the top menu bar, select Terminal, type resetpassword and press Enter.
Close out the Terminal window and behind it you will find the Reset Password utility.
All you have to do now is select the user account you want to reset, enter a new password or leave it blank and click Save.
Then restart the mac from the Apple menu.