A few suggestions for this first meeting:
1. Have a witness (actually this is true for all meetings covered in the Three Strike Process). I recommend that your witness not speak - they are only in the room for HR and legal reasons.
2. Keep it short. Ideally, the meeting should last no more than 20 minutes which is enough time to make your points while allowing for dialogue.
3. After the meeting, send a recap via email to the employee outlining job responsibilities and improved performance expectations. If you really want to send a message, copy senior executives.
Most people will correct themselves after this first meeting. However, if the employee’s disruptive behavior patterns continue, you need to call them in a second time. In this meeting, you outline the expectations again and where they are continuing to fall short again. Next, you put both in a formal, written document on company letterhead. At the end of the doc, include language stating that if the employee does not improve, there will be consequences "up to and including termination" and have the person sign it. This should also be a very short meeting of about 20 minutes or so.
If the employee still doesn't change, the third meeting is when you let them go. This one should take about 10 minutes, tops. (These time stamps are only my recommendation, of course, but if you've given someone multiple chances to improve and they haven’t, there's really nothing left to cover.) Try saying something like: "I'm sorry but you're not meeting the performance expectations required of your position here and we have to let you go." Don't argue and don’t engage in a back-and-forth if they vent or ask you to reconsider. Simply say, "I'm sorry you feel that way but the decision has been made." Again, I know letting an employee go is the worst, most painful part of a manager’s job. But as long as you’re respectful of the individual while being mindful of the team – you’re on the right track.
Emily Bennington is the founder of AWAKE EXEC, mindful leadership coaching for professional women, and the author of Who Says It’s a Man’s World: The Girls’ Guide to Corporate Domination.