Even though it will be black over pink, you really want to cut it out.
To make your screens line up easier, just get yourself a piece of white posterboard, lay a screen on it (make sure to butt it up to the corner, so you have your frame lined up to the outside edge to the side and bottom). Mark/outline around your screen. Now use a yardstick and carefully and making sure that you stay parallel, make both horizontal and vertical lines every 1/4" also making a bolder center vertical line. (all on the board)
When you line up your film on the board, you can place it in the same place everytime, then just put your magic scotch tape on the film and carefully lower your screen onto the film, then rub, adhering the tape to your screen.