The drain pump and trap are behind the bottom front panel. Twist the two catches with a coin and lift it off from the bottom. There's a black rubber tube behind the frame with a bung in the end. Place a shallow tray on the floor and pull out the bung. It has a retaining strap so it can't come out completely. Once drained, the filter (white about 2" across) unscrews for wiping and/or swilling. Then put it all back together.
P.S An old towel on the floor is also a good idea before you start!!
Cheers.
Peter, September 2007