Dear Readers: How do you get rid of a girl I no longer want?

From a male  reader

I want to get rid of my girlfriend but don't know how to go about it. I've been trying for the past eight months to end things up with her but she just does not get it. I have been throwing subtle signs but she's not picking them up. I invited her to the house when I knew another girl will be there but she didn't care she didn't break up with me. I don't reply her pings until two days later and I don't return her calls at all but she still does not get it. I know the easiest way to end things is to talk to her and tell its over but I don't want to do that for two reasons.
She's my friend's little sister and about a year ago she nearly died when she tried to abort a pregnancy for me. So I'm here out of guilt but I am no longer happy and want her gone. She hardly sees me these days or even talk to me but she keeps believing we are in a relationship. I even put on my BB that I am enjoying the single life and I thought she would confront me about it but she laughed instead and said she misses me. I don't want this girl anymore, how can I get rid of her without having 'that talk? A frustrated  fan.