Change current logged in user’s password
Go to Applications -> Accessories -> Terminal, then run the command below:-
passwd
Then, enter the current and new password and you are done.
Change root password
Go to Applications -> Accessories -> Terminal, then run the command below:-
sudo passwd root
Type the following command to unlock the root or administration account.
sudo passwd -u root
You are done. Switch to ‘root’ account with the following command:-
su root
Then enter the newly changed root password.
Hope this helps. Thanks.