HOw do i keep my Apexi N1 Cat-back Exhuast from burning my rear bumper lip?

I got a 2000 honda civic and i got a rear lip for it a while ago but the exhaust burn that lip!! so i just got a new one from wingst west but i think its going to do the same thing so iwant to know what can i do about it. I was thinking on pulling the muffler out a little bit to avoid the burn but how???? Any other ideas. I dont want to get a new different bumper or a different exhaust system!!1 plz if any ideas let me know