To delete a Favorite, simply click on the yellow/red heart for the stock you would like to delete. You will find the heart column on the right-hand side between 'Popularity Rank' and 'Buy.'
After clicking the heart, a menu will appear with three options: Ignore, Watch, or Own.
After selecting 'Ignore,' the stock will disappear and be removed from your Favorites list. You may need to refresh your screen for the stock to be removed from your Favorites list.