Changed MySQL root and now cannot log back in

I am running mysql 5.6 and tried to change the root password following these instructions: https://dev.mysql.com/doc/refman/5.6/en/resetting-permissions.html

I followed the generic instructions at the bottom of the page titled: B.5.3.2.3 Resetting the Root Password: Generic Instructions

I skipped stopping the server and executing the FLUSH PRIVILEGES command. I executed the following command though:mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('MyNewPass');

However, now when I try to log in I receive this error message:ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

Does anyone know where I went wrong?

Thank-you for reading this.

UPDATE:I found this post helpful - how to log in to mysql and query the database from linux terminal

One of the answers works for me where specifying the password directly after the -p instead of waiting for the password prompt. Something maybe wrong with my operating system.