Changing mysql.sys User Password

[Stephen Hawkins]

This is probably a daft question to a seasoned pro but Im a newbiw. Doo I need to change the mysql.sys password?

After doing a:

SELECT User,Host,Authentication_String FROM mysql.user;
to display the mysql users, hosts and passwords I see that the mysql.sys users password is set as follows:

*THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE

Is is safe to change this?
What snippet do I use to change it.
Many thanks.