1. Cut the pages out of the book, as closely to the spine as you can without ruining the spine. I used a utility knife, but an exacto knife, box cutter, any sharp craft-type knife should work.
2. Spread Elmer's glue along the spine/inside of the book with the pages cut out. This helps to keep the spine from breaking and adds a shine to the sides of the spine where there will be no fabric.
3. After the glue is dry, cut a piece of batting 1/4 inches smaller than the book, to line the entire inside. Glue this down, pressing close to the sides of the spine, along the entire inside.
4. Cut a piece of fabric that looks somewhat like this:
Because it was around two in the morning and I was getting lazy, I made the entire thing out of only one piece of muslin, so I only had to sew in four places. To get the angles of the purse right, pull out your handy-dandy protracter and measure angles and lengths to ensure that all four are exactly the same. Or, if you're lazier than I am, you can wing it. My purse opens exactly five inches, with the angles I used. Of course, I can't remember the exact measure anymore.
5. Sew the four corners to create the liner of the purse.
6. Use tacky glue (I used Arleen's, but you can use something different.) to glue the liner into the book. Along the tops, tuck the fabric over the top of the batting and glue both down, for a clean look. Make sure no batting sticks out.
7. You can use a sewing machine to finish the sides of the purse, but I tucked the fabric twice, ironed it, and handsewed a basic stitch accross.
8. Add a button and ribbon to clasp the purse shut. You can also use velcro, on the insides, or a snap or two.
9. Embellish with ribbon or whatever you like.
I tried? If any parts are confusing, let me know, and I'll try to explain them more thoroughly.