I used a small hand pump ( ketchup style pump of ebay for a couple of quid) and emptied the 'clean' washer fluid into a bucket, then removed the whole tank. Cleaned the filters by removing the pumps from the tank and then flushed the tank out. Refitted the tank and pumps and refilled the clean washer fluid back in the tank. I use just ordinary Halfords fluids , but I use the softened water from the house, which should stop or help to prevent sludging up a little.
