No, not the screens. Standing behind the motor, left side above the cavitation plate, there should be 2 screws, the front one is for lower unit oil overflow when filling. The rear screw should be right above the left side screen and should say "wash port" or something similar. Sorry can't get a photo, my boats up at the campsite.
http://www.boats.net/parts/search/Honda/Outboard%20Engine/2005/BF40A5%20LHA%20/GEAR%20CASE%20ASSY./parts.html