In the "My friends" list, there should be a button to delete existing friends.  As it is, a user has to go into a profile to remove them as a friend, but it's logical to be able to perform this operation from the list.

Attached is a picture of how this might look; of course if there are multiple friends, there should be a "X" next to each one.  Whether the "Remove from Friends" text is needed I think probably not.