How do I unfollow someone?
You can stop following someone by going to their profile and tapping Following. This will change to Follow to let you know you've unfollowed that person. People won't be notified when you unfollow them.
To get to someone's profile, tap Explore and then use the search bar at the top of the page to find someone by their username or their full name.
The only way to remove someone from your list of followers is to block them. When you block someone, the blocked person can't see your photos/videos or search for your Instagram account. The blocked person isn't notified when they're blocked.