removing a multislot variable in JESS

I have a deftemplate which contains a multislot in JESS and I want to delete a variable in the multilot if the rule is fired. for example:

(deftemplate Person (slot name)
                    (multislot friends))
(assert (Person (name John)(friends Jimmy Joe Jessica)))

now i want to delete Jimmy from the friends slot.

Thank you very much Ali

Solution

I've fixed some omissions in your question, assuming that the template name is Person.

This rule eliminates Jimmy from all friends of all Persons.

(defrule KillJimmy
    ?p <- (Person (friends $?a Jimmy $?b))
=>
    (modify ?p (friends (create$ $?a $?b)))
)