Step 1: Find a post by the person you wish to hide.

Step 2: Scroll over the post and click on the gray ‘X’ in the upper right-hand corner.
(Please note: The gray ‘X’ may become a white ‘X’ with a blue background as you scroll over it.) 

Step 3: The post will be replaced by three buttons. Click the button on the left.

Step 4: Congratulations! You have completed all of the steps, and posts from the person you have hid will no longer be visible in your news feed.