I had to deal with this problem last year, and it was rough.  The simplest thing to do would be to just block them on your phone or other social media platforms that you talk to them on (if you do).  This would work on your phone, but you will probably have to see them in real life.  If you would like to distance yourself, you’ll need to focus on yourself and not that person.  Find or pursue a hobby that you have.  Find new friends to hang out with.  Focus on self improvement.  This could include your physical and mental health, your time management skills, or other skills you would like to improve about yourself.  I know it would be hard to try and distance yourself from this person, but trust me, if you learn to live without them and prioritize other things over them, it’ll be easier to do.  

I will warn you, however.  This person will most definitely try to talk to you again, possibly asking you questions on why you haven’t been in contact with them.  You can be honest with them on why or you can just tell them that you’ve been trying to focus on yourself lately.  Depending on how this person will take it, they may try to make you the bad guy in the situation.  This could include starting rumors about you or just them telling others that you’ve been ignoring them.  As long as you don’t pay attention to these and continue to focus on yourself, you’ll get by it and that person will eventually go away and you’ll have successfully removed them out of your life.  If this person is someone that you deeply cared about, take some time to seek some relationship advice (if it was a relationship).  As long as you are staying positive and mentally strong in this situation, it’ll take you a long way and you’ll be just fine.  I believe in you!!!