Dyed my hair a warm/golden blonde but want it cool/ash blond?

how do i achieve this? i've tried toners, it hasnt seemed to make much of a difference, would i have to re-dye my hair? btw, i used nice and easy natural light neutral summer blonde, could i use another dye like Live XXL on top of it? i just want my hair to be a cool blonde like lady gaga or pixie lott!