I want to end a friendship ..... how?

I have another question called I want to end a friendship but i don't know how im at the end of my rope? which is what this Q is about as well. Anyways im looking for more solutions as 2 how to end my friendship with this girl who is an attention wh*re and is always lying. i can't stand by anymore more while she cons and lies to people's faces. But mostly im concerned about my other friend i look after her like a baby sister but 2 be blunt she is immature for her age probably about 4 yrs behind. im afraid that if i do get into a fight with said other girl she will get lost in other girl's lies anyways i don't know what to do i don't think that there is a simple ignore her gently path because she already seems to have caught on that i don't want to be friends and is now befriending all my other friends and becoming more aggressive with her pity lies. i really think that she is going to turn everyone against me w/ lies and 4 real im not being paranoid she seems like a psychopathic lier