...
Then, on the right part of the Dialog Box called Effect, change the value of the “Values” field with the identifier of the product you want to add (make sure you type the value matching the Field selected and appearing above). Then change the Effect type to rank, define the position the item should have in the list and make sure to set the check-box “Force include”. Then press save.
...
Remove an Item Rule
Click on the Details tab of the results influenced by an Item Rule (with a green border) that you want to remove.
...