Friend of mine is going to break up with his LTR of 5 months because of disrespect (her refusing to break contact with her ex and hiding it by deleting text conversations). He's thinking about ghosting. Any tips for him to make it as easy as possible?

Edit: Okay maybe I didnt ask the question correctly.

The answers I'm looking for are logistical. Like whats the best way to break up with her, should he confront her about her behavior or just tell her 'It's over' and break contact. What should he say to her to make the breakup as quickly and easy as possible for him. And, to use this as a learning point, WHY do you think that he should he do it that way.

And in addition, how can he get over her emotionally as quickly possible?