ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '<password>';

ALTER USER 'root'@'localhost' IDENTIFIED BY '<password>';

# OR
# ------------
# Not Tested

UPDATE mysql.user SET password = PASSWORD('password') WHERE user = 'root';

# if password column is not available use below
UPDATE user SET authentication_string=password('YOURNEWPASSWORD') WHERE user='root';


UPDATE mysql.user SET plugin = 'mysql_native_password' WHERE user = 'root' AND plugin = 'unix_socket';