“Check Drain” Miele washing machine

Hi, Could someone tell me how to remove the side panels from my miele washing machine (Premier 500) please? The machine does not complete the cycle and says “Check Drain” I have tried to get the side panel off, but it looks like you have to remove the front to get at the last 2 screws. Thee seems to be a lot of Grey gunk and limescale inside the pipes. I have cleaned and descaled the front filter and the external waste pipe, I managed to get at one internal pipe to clean it but I really need more access. Any help would be great before I resort to the miele service engineer (££££).