How do i cut a friendship with my best friend

so context, i have had this best friend for like 3 or 4 years but we´ve been friends long before that. The point is that im getting tired of her, not latley, but like for the past 8 months. Ive tried ignoring her and everything but she wont just go away. This year we entered a new school with all my generation (20 ppl lol) from last year and i want so bad to make new friends and get away from my old "friends". So i have a lot of reasons to leave this best friend but like she wont stop following me everywhere i go, does the same stuff i do, watches the same stuff, signs up to everything i sign up and its so annoying. I need to get rid of her so bad, please help! guys ik u see this posts pls any advice ca help