Step 2: Get your backups in place

Before firing an IT employee, make sure someone else knows what that person does -- and how to do it.

"You need to structure your IT organization so that no one is indispensable," says Robert Monroe. Now a management professor at Carnegie Mellon University, he spent 15 years in software development and management.

One of the biggest obstacles to firing someone: They may be the only one who knows how to perform mission-critical tasks. Monroe suggests breaking these "information hoarders" of their bad habits early on.

"Always, always, always operate on the premise, 'What if you get hit by a bus?'" he says. If that should fail to sway the hoarder, point out three other, more self-interested truths: People who don't have reliable backups can never go on vacation. They can never take sick days. And, he adds, they can never be considered for a promotion to a more interesting and more highly compensated role in the company.

However, even when dealing with an information hoarder on the emotional front, be sure to implement some tactical fail-safes. Monroe recommends rotating assignments among members of an IT team, in a phased way, so that everyone can absorb the skills and information to do critical tasks.

If an IT department is tiny, Monroe says, managers can strive for some redundancy. "Make sure people are familiar with the work that other members of the team are doing."

Step 3: Do it fast

But how to actually pull the trigger? Jim Lanzalotto, a vice president at outsourcing agency Yoh, suggests going to the movies. "Have you ever seen the movie 'Office Space'? Do the exact opposite of that."

He explains, "What they do in 'Office Space' is bring in the efficiency experts and pretty much prepare everyone to be fired. It creates a feeling of edge in the office - it's the exact wrong thing to do in an organization."

If you're going to fire an employee, make it quick. Monroe recommends having a standard process for everyone who's leaving the company. This process should include a checklist of things to do to remove access to crucial systems, as well as an exit interview that reviews key points in any confidentiality agreements.

Stefan recommends packing the exit interview with questions that'll help keep operations running smoothly. For example, find out what passwords the soon-to-be ex-employee has and what systems they're for, and give the person a checklist of items that need to be accounted for or turned in.

While the exit interview is going on, he says, someone should be checking to make sure that any potential evidence that would justify the firing isn't being erased or corrupted. Another IT person should also be locking down the system and preparing to force a company-wide password reset. That way, the ex-employee won't be able to log into the usual systems with another user's ID and password.

While such preventative actions are wholly appropriate, they don't mean you should treat the employee as a criminal. "When you terminate an IT person, you still have to deal with them in a respectful, professional manner," he says. "If you need information, treating [the fired employee] like a criminal makes them not want to respond or give you bad information or damage the system."