I have purple hair dye, and am worried about bleaching...?

I got this hair dye that comes with bleach and says for bright purple bleach it first and for more subtly color do it over your reg. hair. Well, I had hot pink streaks died in my hair with a kind that didn't have to bleach first, but i am worried to bleach my hair cuase i've never done that and i dont want my hair to break off if i dye it purple and then have to keep dying it back as it fades... what would you suggest... bleach, no bleach---etc... any advice is welcomed.