I still have not yet figured out how to diagram with a keyboard, but maybe I can describe what I would do about the boldfaced words. The two prepositional phrases I would make compound and then take short horizontal lines to the left from the prepositions and from those short lines run sloping lines down. On the sloping lines I would put "tonight" and "morning". From "morning I would similarly take a short horizontal line to the left and from it a sloping line down. On that last sloping line I would write "tomorrow".
I guess you could say that there is an understood preposition before "tomorrow morning" and do it a little differently.
I would demonstrate the modifications from the prepositions as a way of showing that the whole prepositional phrases are being modified.
Maybe I will see if H&H has anything like this.