Reference: http://jingyan.baidu.com/article/495ba841ef412d38b30edeb2.html
1. Open cmd and enter mysql -uroot -p and press Enter
Enter the original password
2. After successful login
输入 mysql> set password for root@localhost = password('123456');
Change the password to 123456. Note that there must be a semicolon after it. A semicolon is only a command.
that's ok