How should I do this?

So this story may be long, but I'll try to make it as short as possible. I'm 21 years old and my "bestfriend" is 22. When we were 19 and 20 we got into a big argument and one thing led to another and next thing you know everything was blown out of proportion. We ended up having a fist fight, which I initiated, I won't lie. I came to her house and she had every right to defend herself for me doing that. So after we fought I still let her know that my love for as a friend will always be there because we grew up together and we had been friends literally since 2nd grade. Anywho, she disregarded that and told me "fuck me". After the fight she started putting nasty things about me on Facebook. Old pictures of me acting silly that I would send her when we were friend (obviously pics that were ugly as hell that should be on fb). She's put them up to be funny. And then she did the Most disgusting thing ever. She put a video of me and my boyfriend (at the time) having sex on Facebook. She exposed me......... How she got the video?! My dumb ass trusted her enough to send it to her a longggg time ago. Why? I don't know!!! Young and dumb that's why. She not only put it on fb, she sent it to some other guy to put on his page as well. So after that I told myself I'd never talk to her again. Well here it is 2 years later, and she calls my house phone begging and pleading to get our friendship back. So me being the person I am (gullible) I accepted her back into my life as my friend. But now I'm noticing some things that I should've noticed about her a while back. She's a big liar, she also talks about a lot of people she's supposed to be friends with, and I'm starting to see right through her all together. I don't know why I didn't see this stuff before........... but it's showing big time now. My question to you all is, how do I cut this friendship back off for GOOD. I don't want to be her friend anymore because she's not my type of person anymore. At all! Should I walk away without saying anything? Should I tell her and be honest about it, or what??