Oops. My bad, I re-read my question and looked at the pic a hundred times. And I wasn't able to comprehend my own question.
I reuploaded the pic to delineate that the trill on the L.H is played on the treble clef.
It's either nobody played this sonata, or someone solved it but is unable to describe it by words. Or the piece is too advanced for me.
To those with experience., how did you handle/practice R.H taking a G note from a trilling L.H(F-G).
I want it to be as clear as possible. Since it one of the main challenges of this piece.