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