I can't picture it in my mind, but when I have trouble with screws, I use a helper. Get a pair of needlenose vice grips, and try to grab the sides of the screw. Use in conjunction with a screwdriver and they practically jump out!
Were you able to get your pump to shut off by unplugging and plugging in your relay?
Were you able to get your pump to shut off by unplugging and plugging in your relay?