sudo /usr/local/mysql/bin/mysqld_safe --skip-grant-tables

2016-06-12T08:29:17.6NZ mysqld_safe Logging to '/usr/local/mysql/data/lyqdeMacBook-Pro.local.err'.
2016-06-12T08:29:17.6NZ mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data

/usr/local/mysql/bin/mysql

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 37
Server version: 5.7.13 MySQL Community Server (GPL)

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owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

mysql> use mysql;

Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> 

mysql> update user set authentication_string=password('root') where Host='localhost' and User='root';

Query OK, 1 row affected, 1 warning (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 1

/usr/local/mysql/bin/mysql -uroot -proot

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

mysql> alter user 'root'@'localhost' identified by 'root';

Query OK, 0 rows affected