When I'm trimming the overlapping blenderm from the hinge gap, I use a really sharp pair of canopy scissors. I first make a small cut at the end of the over lap and then lay the scissor blades, which are slightly open, flush with the surface. Then while holding the cut end of the blenderm, I just run them along the edge until all the overlaping blenderm is cut flush with the surface. Works every time.

J