Water and electric has to be turned off and disconnected first then the discharge pipe work watch disconecting the NRV as the pipe is full of poo once drained and removed undo both screws and lift the pan and cistern clear and forward to safe place to access the macerator box in the back of the pan remove the box and clear the blockage and replace the lot it's not easy fraught with problems and easy to cause more dammage than the machine costs so sorry to say you need experence to do this job so a propper Saniflo service would be required.
Muncher
November 2014