On my '21 R31, I remove the front v-berth cushion. Turn yourself into a small contortionist, semi climb in and remove the clipped on cover, keeping in mind the orientation. Jiggle and pop the screen out, clean, and reverse the proceedure. I found that liberal applications of blood and "F" bombs smooths the process. It's also very important to check for leaks whilst holding a beer afterwards. (Any beer with the word "Lite" in it's name will cause the float to stick and your friends to make fun of you).
Alternatively , bring the boat to Poulsbo tomorrow and I'll help you. (drink beer, not clean the sump)
Steve