Unfollowing and unfriending are separate — you can stop seeing someone's posts and stay friends with them.
From their profile
Click the Following button. You'll be asked to confirm: «Are you sure you want to unfollow this profile?», with a note that you'll stop receiving updates from them. Click Unfollow, or Cancel to leave things as they are.
From Connections
Open Connections in the side menu and choose Following.
Find the person — the search box above the list helps if it's long.
Click the three dots beside their name and select Unfollow.
Here there's no confirmation — the action happens immediately. That's true of everything on the Connections page, so take a moment before clicking.
What stays the same
Their posts stop appearing in your feed, but you're still friends and can still message each other. You can follow them again at any time.
It works the other way too: removing someone from your friends doesn't unfollow them. If you want neither, do both.
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