Yamaha N8 mixdown?

Hi, Just spent 4 hours painstakingly following the rather vague and enigmatic instructions of the N8, I’m trying to send a recorded track from a Cubase project back through the N8 and add reverb to it (and compression) before recording it to a new track in my project…according to the instructions it’s a doddle…but I (with the help of another more able minded person than me) just get nowhere…gone through the instructions letter by letter and it a’int happening,

is there an N8/12 user out there who can help please?

thanks, Kevin