On measure 47, keep the same left hand position used in the previous measure and play these artificial harmonics by lightly touching the strings on the 24th fret with the right hand index finger while striking simultaneously in an upward motion across the fretboard with the r.h.ring finger. Considering that the 24th fret is outside the fret board, you have to practice a fair amount to identify visually and manually to reach the right spot.
The 12th fret harmonics in measure 57 are stroked with the right hand thumb strumming the 6th, 5th, and 4th string follow by the right hand index playing the 3rd string, the right hand middle playing the 2nd and the right hand ring playing the 1st. This quick arpeggio is reminiscent of what an harpist does when he/she strikes multiple strings in a fast passage. After striking the harmonics, bend the guitar neck with the left hand by pushing the headstock away from you first, and back to the original neck position second. As you perform this bending movement make sure to keep the tempo.