I cut it with a big pair of pruners. It cut right through nicely. (Its a little tricky cutting in the 'dip') You can also sand any rough edges.
Then I spray painted them lime green, and once completely dried, I hung them up by drilling little holes in each (2 for small, 3 for big gutter) and used small screws to hang up. I also sanded a few spots to distress them a little. I don't think they would hold a whole lot of weight, but I did want at least 3 books on each. At first the books sat too low and you couldn't see the titles enough, so I put 2 wooden toy blocks under each to pop them up a little. Styrofoam would work nicely if you had the right size.
My 3 year old son LOVES his reading corner.