I work in the office of the company. Yesterday, I informed some leaders of the company to have a meeting. I sent it to a former leader by SMS (now I have resigned)

First, send him a text message to explain the situation, and then call him to apologize sincerely, emotionally and rationally, and try to persuade him not to make trouble in the company; If it really doesn't make sense, give special instructions to the security guard not to let him into the company and stop him at the door; If he makes trouble at the company gate, he can call the police. Remember to leave the text message sent to him, and leave the evidence on the telephone recording.

Secondly, delete his phone number from the short message group to avoid similar misunderstanding again;

Third, write a written self-criticism on your own work mistakes and give it to the head of the department. When no one has done anything wrong, it is important to have the courage to admit the mistake and correct it after knowing it. Attitude is very important.

I hope I can help you.