The spray bars have the 2 little square clips that clicked onto the next piece. You have to lift them up simultaneously and pull the spray bar off. I have found it easier to pry one up with a very small screwdriver and just pull at the other clip with my fingertip (one hand holding one piece and the other pulling on the spray bar). Be careful not to lift the clips too much so that they break. Actually, after taking mine off and on a few times, they no longer really click back and they're easier to pull off now, too. Hope I won't eventually see a flying spraybar.
Besides brushing the inside, I have found twisting Q-tips in the holes works great, too.