I normally just use a scrapper and pull off everything around the teeth. Anything stuck to the plumping you can pull off by hand. If you really want to scrub it, pull out both plumbing tubes, the overflow will drain into your sump (as well as some tank water, so make sure you have room in the sump). You can then use either of the brushes Hiker was refering to. Keep in mind, what ever loose stuff you are unable to pull up, that is gonna end up in your filter sock/sump.