Bleaching colored hair at home? Do I use a color remover or just start bleaching?

My hair is a medium to dark brown color, my goal is to get to a medium to light blonde. It has permanent dye with semi-permanent on top. So should I use a color remover like color oops first? I've heard negative things about hair color strippers so I'm weary. I've used bleach before but not a stripper. So should I start the bleach process or strip it first?