The first rule od a succesful breakup is stick to the plan no matter what. He will try to disturb your flow of thoughts, he might even cry or fall on the floor and start kicking, shaking, foaming and shit. Do not let that disturb you. Focus and get on with it.
If in trouble and you run out of words use the “it’s not you it’s me” phrase. It always works without exceptions. You will boost his ego a little while dismantling it. It’s a mind fuck so use it. It’s a fucking light saber so use it. Be the Jedi.
From: How to break up with him in under ten minutes