The process is pretty simple. Cut the bottom of the handle off just below the buttons. Cut the display off just above the buttons. Trim the little antenna do-dads off, and then carefully cut lengthwise to make the display and buttons pieces half as thick. If you're careful doing this, you'll actually be able to use the back sides of both the display and the buttons, glue them together and make a second flip up auspex in the closed position. Now it is just a matter of trimming carefully to fit the auspex on the forearm of the model, and smoothing out the edges of the display with a file. The fist on the arm is from the Grey Knights sprues.