Instagram has no function to remove followers. However, if you do not want these non-friends to view or comment on your posts, you can choose Block, Restrict, or Report the user. The steps are:
Step 1, Log in to your ins account, then visit the homepage
Step 2, Click on followers to see your follower list.
Step3, Choose a follower and visit his homepage
Step4, Click on the arrow in the upper right-hand corner, you will see the options to block, report, and restrict.
If the above steps are complicated for you, you can use a bulk block non-friend marketing tool Followinglike to help you complete this process easily and quickly. And before blocking, you can also filter your followers. For example: Exclude non-friends, exclude friends who have not been active recently, exclude friends with a small number of posts, and exclude friends and fans with few.