How do you tell your close friend that you really like her?

You first get her alone, no friends around (not yours, not hers).

Look her in straight in the eyes, and tell her you have a question for her and when she says, "What", say "Never mind, it's stupid". And then, if she is persistent that you tell her, you simply start out like so, (look down from her eyes) "[name], We've known each other for I don't known how long and I really like you a lot...". Stall for a moment, look up to see if she is looking at you, gain eye contact!

Then ask her if she likes you. If she says Yes ask her out, and if she says No, ask her, "Why not...". If she gives you a legit reason as to why she doesn't like you like you, tell her, "Thought so..." and just sort of walk away.

Don't be stupid. Make sure she is available before you ask her!!!