(defun replace 
       (array old_value new_value)
       (cond 
            ((null array) array)
            ((eql old_value (car array)) (cons new_value (replace (cdr array) old_value new_value)))
            (t (cons (car array) (replace (cdr array) old_value new_value)))
       )
)

(setf a '(6 5 4 3 0 1 5 3 3 1)) 
(setf b (replace '(8 1 8 2 3 8) 8 5))
(print b)