Any tips on cutting a fiberglass tub surround? My bathroom window is orientated such that it overhangs into the area where the tub surround will go. The fiberglass tub surround is a 5 piece heavy duty style. I was going to attempt to leave the window trim off and just cut around the window opening, but then I would have to shave off some material on the window trim to get it to look right. I am going to put the window trim back on, transfer the dimensions to a piece of cardboard and then transfer those dimensions to the fiberglass piece. Jigsaw with a fine blade? These cuts need to be extremely straight!