You don't. Just avoid them, don't flirt, don't laugh at their jokes, and they'll eventually get the picture. Don't be too obvious about it; don't be rude, just boring. But there are always people that just won't give up. As a last resort, you could ask a friend to tell them for you. Have them just hint at it. DON'T have them say "hey, Samantha, Fred told me to tell you that he doesn't like you." And pick someone that is good friends with the person; someone that the person trusts. Another thing you could do is make up an excuse. My excuse that I use often is "I don't date younger girls", which is partly true. Another thing you can do is talk constantly about other girls (or guys) when she's (or he's) around you. Just be like "Wow, that girl (or guy) over there is hot" or "I miss (either your ex or your crush's name goes here)"
tell him/her you dont like that person
Just tell them you dont want them and if its someone who you dont like getting emails from, block them.
tell them you dont
tell him/her that you dont mean to break the ice but i kinda like you and please dont tell anyone, if he is a person who spreads rumors just dont tell the person
you dont
i really dont know so someone tell me
be honest if they like you like that tell them I think it's better we remain friends
Hey ......... I just wanted to tell you that I like you. If you dont like me then im cool with that but i really like you
Get with that person and dont tell anyone.
Just say '' Hey I like you whether you like it or not."
Tell them to seglum.
simply tell them how you feel! when i find out someone likes me and i like them back, i get super excited! if you like them back, tell them. and if you dont' break it to tem nicely :)