Article: It's located at https://www.instagram.com/. If you're already logged into Instagram on your computer, this will take you to your Instagram feed. If you aren't logged in, you'll first have to enter your username (or phone number) and password in order to access your account. This is the person-shaped icon in the top-right corner of the Instagram feed. Doing so will take you to your account page. It's the section below and to the right of your username that's at the top of the account page. Doing so will open a list of the people who you're currently following. The "following" section has a number before it that represents the number of people who you follow. Doing so will unfollow it; you should see a blue Follow button appear where the Following button initially was. Once you finish, there will no longer be anyone in your "following" list. Some Instagram accounts will require you to wait for an hour or so after unfollowing 200 accounts before you can continue.

What is a summary?
Go to Instagram's website. Click your profile icon. Click the "following" section. Click Following to the right of an account. Repeat the unfollow process for each account you follow.