How to shut down your feelings towards a person

You need to distance yourself, don't contact or talk to this person. Surround yourself with things that make you happy and let time do its work.

Agreed. You can't turn your feelings off. They will just have to fade with time and as you put more distance between yourself and this person. What you can do between now and then is simply find another focus, something to distract yourself from your feelings.
If you don't mind me asking, why do you want to shut down your feelings anyway?