Instructions
Play through the second chapter of the third school year until you're asked to feed Buckbeak. Press the stylus to the screen where the meat appears, and then draw a line with the stylus to Buckbeak. The meat will follow along this path until it reaches Buckbeak.
Move three pieces of meat in all; Hagrid will then warn you that Blast-Ended Skrewts are trying to get to Buckbeak. They will appear at the lower-right corner of the screen.
Draw a line from Harry Potter to the Skrewts with the stylus. This serves as a repelling spell when it hits the Skrewts and will cause them to turn around. Cast this spell on the two or three Skrewts that appear to drive them off.