How to get rid of a pesky ex?

Can anyone give me some advice as to the best methods to get rid of a pesky ex-boyfriend?

Girls and guys, please do give me some insight.

I should note that its my current girlfriend's ex that I want to get rid of not my own ex.

Tell her not to answer her phone calls from him and not respond to him any way (messages / emails)

If the calls continue, pick up the phone and have a chat with him. Be firm. That should stop him.