There's a reason its so difficult: you are basically taking away someone's livelihood, and deserved or not, this is always a painful experience. There are ways to do it appropriately, and to make sure that you treat the person you are firing with dignity and respect while helping them transition back to the real world. Here are some pointers:
- Make sure that this won't be a surprise: During the person's employment process, have you been giving them honest, open feedback? If not, you need to start. It simply isn't fair to fire someone with no warning (unless circumstances dictate), so make sure that you are giving someone feedback that gives them an opportunity to change. Warnings during the employment process is also fair and appropriate.
- Keep good records: You may have had plenty of conversations with an employee about the behavior that has led to their firing, but if they sue, verbal conversations aren't enough. You need to keep a clear, written record of the behavior that led to the firing and documentation that you have given the employee ample warning.
- Be short, and be direct: Don't beat around the bush. Don't avoid saying it directly. Tell someone, upfront, that due to whatever the reason, their employment has been terminated. If possible, have someone else present in the room, just in case the employee starts making threats. Let the employee know what their severance package is and what other options within the company that they may have.
- Get them out: Do not let an employee hang around the office - in all likelihood, they will poison your office moral (and who can really blame them?). Get someone out of the office as fast as possible after you let them go.
- Is it hard on you? No one cares: Don't tell the employee you are firing how "hard on you" the decision is. They are losing their job and are devastated. They don't care how difficult it is for you, and saying so just seems insensitive.
- Be empathetic: When you are firing someone, you have a job to do. That being said, you have to treat the person you are firing with dignity and respect. Respond to their needs and be kind. Have a box of tissues available if need be.
- Be ready: Make sure that you have all your bases covered. Do you have a legal waver in case someone might sue? Do you know exactly what the compensation package is? Has HR and/or legal cleared the firing? Do you have your letter of termination and anything else that human resources might require?
- Listen: The outgoing employee will likely unload, telling you how unfair the situation is or just how painful it is. Regardless of how much their words may hurt you, you should be prepared to listen. Firing someone isn't easy - but cutting someone off who has been fired is just rubbing salt in the wound.