Unfortunately it appears to be impossible to comply with all of the requirements within the instruction manual without moving the waste pipe down several inches (i.e. knocking a new hole in the kitchen wall and filling in the old one). Between requirements for "install this thing through which the pipe must run X cm above the top of the pipe", "make sure that the pipe runs at least Y cm from the thing through which it runs to the top of the waste pipe" and "make sure that the waste pipe is at least Z cm long", it simply cannot be done.
And of course we got the pipe home to find that the old pipe must have been imperial measurements and the new one metric, 'cause they don't actually fit together in any case.