I've just ordered a k and n air filter for my drz and when it arrives I'm going to do 3x3 mod and get it set up and jetted. Basic question. How do you remove the foam filter. I had a quick look and it looks like take the clip off and pull off the filter. Is it that simple? I had a look for a filter change thread but couldn't find what i was looking for. Also when fitting the k and n is there anything i should do to it such as spray it with oil or does is need sealing with grease at the rear like the foam one?