One of the worst parts of being a leader in a company is that not every employee is going to be useful and sometimes people have to be fired. It is not a pleasant experience for either parties and is not something that should be taken lightly. Before moving into the firing stage, it is important that the employee is given warnings or chances to change their behavior. When a problem is identified with an employee, make sure to document the issue and the steps taken towards trying to fix it. Firing an employee is delicate business and you need to be careful how you go about it.
As stated before, employees need to be made aware of any issues with their work or behavior and given a chance to improve. When you point out these issues or another employee comes to complain, WRITE IT DOWN. Document everything that is said or done when it comes to disciplinary actions against one of your employees and make sure that Human Resources is also aware of what is going on. You do not want to find yourself down the line without any proof of their misconduct or the chances you gave them to improve. Hopefully a warning will encourage your employee to straighten out, but always be prepared for the worst. If you are not ready to cover your butt when some angry ex-employee sues you for wrongful termination, then you are going to be in for a headache trying to defend your company.
When it comes time to sit down and fire an employee, take a few steps to make sure the environment is right. You should have them come to your office or some enclosed area that does not allow others to overhear; also, make sure there is another witness in the room to vouch for how the situation unfolds (usually this will be a representative from Human Resources). Be straightforward when addressing the employee and make sure to reference the warnings that were given before it came to the firing. There is no need to be unnecessarily harsh but be clear that they are no longer meeting expectations and are fired. You may need to give them time to process your words and be prepared for sudden anger or tears. The whole point of having another company representative in the room is to make sure that A. you are safe if an employee acts irrationally and B. they can bear witness to your method if it is ever called into question. Once the deed is done and the employee has filled out any necessary paperwork, give them a chance to say goodbye and clean up their desk. Do not rush the process because even though this person no longer works for your company they deserve respect as they leave.
Firing people is unpleasant but a necessary evil of working at a company. You need to make sure that you have the best suited people for the jobs you are working. In the end, firing an employee will be the best for both your company and the person.