Need to evict my friend. Should I avoid giving him a somewhat harsh written notice?

I agree with Ticomaya on this point. Telling a couch-surfer to leave is not a legally-subtle thing to do. The language of the internet form is almost a parody of legalese. It seems optimized to sound lawyerly, not to express anything substantive. If Tennmakk wants to rephrase it in plain English, there's no reason not to do it:
_____________________

Dear <Name>,

ever since <date>, you have been sleeping on my couch in my apartment at 1060 W Addison St, Chicago, IL 60613. It has been nice to have you, but I am sorry to tell you that this arrangement cannot become permanent. Please move out of my apartment by <date>, and take your belongings with you.

Best regards,

<date>, <signature>
______________________

That's really all Tenmakk needs to say, especially if he or she is not a lawyer. For example, consider language like "Your tenancy . . . will terminate". Does Tenmakk, not being a lawyer, know for certain that the friend is legally a tenant? What if he's not? Now he has a letter where Tenmakk testifies, in writing, that he is. Or how about this? "[Y]ou are now hereby required to surrender possession of said premises. . ." Is the friend legally in possession of "said premises"? Maybe not, but if Tenmakk mindlessly copies a legal form from the internet, he now has a written document proving that he is.

Ticomaya, to repeat, is right: Tenmakk ought to write a plain-English letter telling the friend what he needs to do and when he needs to do it. This is especially true because Tenmakk is not a lawyer. Copying and pasting language you don't really understand, just because it sounds lawyerly, will likely come back to kick you in the butt if you're a legal layperson.

Oops. I just realized something. I meant to post this in the "friend" discussion. :/

No problem; you can always add a tag like "relationships" or "friendship" to your topic.

Not my area at all, but I agree with Thomas and Tico.

If it's not in writing, at the end of thirty days he may still be camping out on that couch and refusing to budge. You really need a specific and documented time of departure.

you might get hit by a bus tomorrow, that does not mean that you should make plans around getting hit by a bus tomorrow.

It is probably just me, but I like to assume that the people that I have picked as friends are decent people.

Indeed. Hope for the best.

I'd level with him first. I think your eviction notice isn't quite the right thing for a friend.

Following up on JoeBlow's point: what friend-to-friend things have you said to him so far to let him know that you want him to leave? Since you got yourself informed on legal forums, I assumed you already had the friend-to-friend talk, he's not leaving, and now you're preparing for the next step. But on re-reading your posts, I don't see you say anything to justify this assumption of mine. So tell me: what did you say to him so far?

I read none, that OP wants this guy gone yesterday and is unwilling to take the chance that friend to friend conversation would not get him out fast, thus he would be stuck with is house guest for more than 30 days. He wants to make sure that this is over in 30 days.

I'd suggest doing both. Start with talking with him to make it personal and less harsh. And then end it with the note. Maybe say something along the lines - here is a written notice to avoid any confusion.

Clearly things aren't good between you and him if you're having him move out.

What you're saying is, you know he will lose his job if you kick him out. So, that must mean you aren't a very good friend. So why even say you're worried about his feelings or your friendship if you know that its going to be harmful to him.

I don't know the circumstances, I just find it a bit contradictory to what you're saying. You want to stay friends, but then you know what you're about to do is going to harm him. So to me, you guys aren't really friends.

However, what I would do is tell him you're not comfortable with him crashing at your place anymore for w.e personal reason, he should be able to understand that, but let him know that you'll be there to help him find another place to live. That's what a friend would do.