just completly cut them off, and when they ask if u wanna chill just say u cant cause u got plans with someone else or dont even reply and if she/he wants to chill @ skoo then just keep walking away and find a new group of friend to kick it with until she gets the idea but warning she is probaly gunna talk bad about u in the future and if she does then that just proves shes fakee
There is no easy way telling someone that you don't want to be friends anymore. The best way is honesty and the reason why you don't want to be their friend anymore. There will be hurt feelings on both sides. I wish you luck and the best.
Ignoring and not talking to them is a bad idea. It will leave them with a lot of bad feelings and isn't very mature. The best way is to talk things over with them without any blaming, get an adult to maybe help you with it too! They will still be upset, but will hold more respect for you:)