Joser, as I said once before here, disgruntled employee is (or should be, a contradiction in terms. You need to help them become gruntled (??) or help them become an ex-employee. If the job you help them find makes them happy, it is a win-win. They will be an ex-employee, but not a disgruteled ex-employee.
Al Miller, CRCM
Opinions expressed are my own and not necessarily shared by my employer.