FORTUNE — Dear Annie: I’ve been following your columns about promotions over the past year or so, and I finally got one. The trouble is, it comes with some nasty conditions. The person who had this job before me let my department’s performance slide to an unacceptable low, mainly because he didn’t want to fire anybody — even though there are a few people here who haven’t done any real work in years. These same people have also influenced other team members, so their productivity has fallen too.
So now what I have to do is “turn things around,” my boss said, by letting a few people go and giving shape-up-or-ship-out evaluations to some others. I have no experience with giving this kind of bad news, and I really dread these conversations. Do you or your readers have any advice on how to do this, or how not to? — Management’s Messenger
Dear M.M.: “If you were hoping for a way around the unpleasant emotions that accompany the delivery of bad news, I’ll have to disappoint you, because there isn’t one,” says Geoffrey Tumlin, who heads Austin-based communications firm Mouthpeace Communications and wrote a new book called Stop Talking, Start Communicating: Counterintuitive Secrets to Success in Business and in Life.
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Tumlin gets where you’re coming from. He is often called in when managers have put off doing the inevitable for so long that whole teams and departments have crashed. “It’s amazing to see how problems can cascade through an organization because no one wants to get rid of a problem employee,” he says. At the same time, he understands why bosses like your predecessor procrastinate: “Firing people is hard.”
Nothing can make it easier, but Tumlin offers four tips for getting it done:
1. Get straight to your core message. “Your core message is easy to identify, because it’s always the thing you don’t want to say — whether it’s ‘We’re switching vendors’ or ‘We have to let you go’ or ‘We should stop seeing each other,’” Tumlin says. So get straight to the point. “Trying to sugarcoat it won’t help, and may even confuse the other person, which just makes it harder for them,” he notes.
2. Stick to your guns. If you’ve ever been talked out of a decision, you already know how tough this one can be. “People will say things like, ‘But we’ve worked together for 15 years! You’re not really letting me go, are you?’” notes Tumlin. “Or they will try to talk about the reasons. But resist the temptation to get pushed, cajoled, or charmed off your message.”
3. Explain yourself, but not too much. Tumlin recommends fitting the message and the reason for it into a single sentence — for instance, “We’re letting you go because we’re taking this whole department in a different direction.” If you want to say more, that’s okay, “but do it by repeating the point. Don’t add any new information, or you’ll encourage the discussion to drift away from what you need to say.”
4. Get out of the conversation. Letting the discussion drag on is usually a mistake, Tumlin says. “Naturally you can answer factual questions like, ‘When’s my last day?’ or ‘What happens to my 401(k)?’ or offer to get any practical answers you don’t have,” Tumlin says. “But beware of trying to answer any speculative or probing questions, again because they can confuse the issue and drag you away from your point.”
In this situation, Tumlin adds, “It’s a simple formula: Be clear, be concise, and be gone.” The not-so-hot evaluations you’ll have to deliver are, however, a different story. “An evaluation, even a negative one, is really the opposite of firing someone,” he notes. “That’s because it should be an ongoing discussion, not a one-time event, and because you’re hoping to keep the people you’ll be speaking with, assuming they can get better at their jobs.”
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With that in mind, Tumlin advises you get the firings over with first, and then wait a bit before giving feedback, for two reasons. First, firing someone — say, an employee who’s a known slacker — is a form of feedback to the whole team, he points out. “Everyone will be watching, of course, so give it a couple of weeks and see how that percolates through,” he says. “You may find that some people’s behavior changes for the better.” If so, you’ll have one less tough topic to tackle.
Second, Tumlin says, evaluations that make a difference require specific examples of the behavior you want to change. “The least effective feedback is always too general, like ‘You’re not good with clients.’ That doesn’t tell the other person anything useful, and it’s too easy to dismiss,” Tumlin says. Instead, a particular example — “You talked over Client A in that meeting last Tuesday” — tells exactly where an employee needs to focus her efforts.
“You’re new in this job, so maybe you don’t have an example yet. But if you want these evaluations to matter, wait until you do,” says Tumlin. “It shouldn’t take long.”
Talkback: If you’ve ever been fired or had to fire someone, what made the bad news more (or less) bearable? What was the most useful evaluation you ever got? Leave a comment below.