Morning,
i have both the 10 and 20, so cant see the 30 been any diffrint, as mentiond in the previous post, turn off, turn the taps off,, unscrew them, then unlock the blue catches,take a firm grip and open, then just open over a towel, thies filters can be a bit stiff to open, as for the what ever you want to put in it, just use a filter bag or equivalent,
i have found them to be pretty good and fairly quite as well!
just a spot of advice, give the O ring a good clean when you clean the filter, also the pump head on the inside has the 2 wholes, take a grip and give it a anti clock wise turn to get to the impleller and stuff!
good luck