Pump screens in wells keep gravel, sand and other debris from coming up the well pump with the water. If the screens get too full of sand, however, the water won't flow properly. Removing the buildup from the screen is the only way to improve the water flow. While you can't simply remove the screen from the well, you can use the suction pump to clean it.
Turn off the well and disconnect your suction line from the pump.
Screw the suction line to a garden hose and make sure you have plenty of water in your holding tank.
Turn on the hose full blast. This will clean the pump screen by pushing all of the debris away.
Turn off the hose when you run out of water. Hook the suction line back to the pump.