Weather Watch Ice/Water Shield Question

Hey guys, The instructions on the weather watch ice/water shield are a bit vague. Obviously, you pull off the white plastic on the back to adhere it to the roof. My question is, what is the little adhesive strip on the other side that faces up once installed? I assumed it was to adhere the shingles to the ice/water shield, but the dang white plastic seems like it's melted to the little adhesive strip and is almost impossible to get off. (it's about 4" wide at the bottom of the ice/water shield). Are you supposed to remove the thin white plastic from that adhesive strip, or is it meant to be left on?