It happens all the time. As a manager of people for over 20 years, I learned a lot of basic rules how to hire, onboard, manage, lead, motivate, layoff and sometimes fire my staff.I saw my colleagues consistently fail in just one area — when someone on their team gave their notice to leave. So I have some tips on how to handle it and make it a win-win-win for you, your soon-to-be leaving colleague, and the company.