How to add friends to a custom list or smart list 

To add friends to a custom list or smart list from the tips below:

1. Click Friend Lists under Explore on the left side of your News Feed

2. Click the name of the list you want to edit

3. Click Manage List > Edit List

4. Click On This List > Friends

5. Search for friends, then click on their name to add them to the list

6. Click Finish.

See: How to turn off Facebook messenger notifications

How to remove someone you’re friends with from a list 

To remove someone you’re friends with from your friend’s list, follow the steps below:

1. Click Manage List > Edit List

2. Click on a friend’s name to remove them from the list

3. Click Finish.