Privacy Problems
Sometimes, Instagram users with public profiles wants to turn their account to private. This is when users wants to make their account more personal, meaning what the user follows really interests that user and also making sure that he only able to share instagram pictures to people he wanted to share with.
Remove Followers
Instagram has an option to turn your photos into private photos. Problem solved? Not yet, since the user may have existing followers he really doesn't know personally, even worse - spammers. Luckily Instagram also provides the facility for users to block other users. But you don't want to block everyone on your list. There maybe some that you just wanted to disconnect with, temporarily, for what ever reason is. check the procedure below
Block them and then Unblock
Actually the steps you need to do to remove a follower involves blocking the user (but its just part of the step), but you will not be blocking them forever. Here is how to remove followers after you've set your settings to Private :