First step was to clear everything off the shelves, then take out the two removable shelves and lay it on its back.
Besides the bookcase and cool wrapping paper, I used an xacto knife, some scissors, and some repositionable stencil spray. Not only did I not have any spray glue in the house, but I also wanted to be sure I could remove it if I didn't like the effect (or wanted to change out the paper in the future). Reading the instructions, I discovered that if I sprayed the paper and the bookcase back, then let both dry, I should get a reasonably firm bond. Okay, so on to the cutting!
I started with a sheet of paper just slightly bigger than the area between two nonremoveable shelves. After spraying adhesive on the paper and the bookcase back, I started smoothing the paper down. It took some practice, and I discovered that I shouldn't worry about starting right at an edge of the paper. The design of the paper has no straight lines, so it doesn't matter if things are a bit crooked.
After smoothing the paper to the back of the bookcase, I used the knife to cut right in the seam between the two pieces of bookcase. This was one of the hardest parts. Be sure that if your fingers get caught between the knife and the bookcase, you move the knife first, not your fingers. I'm sure you can figure out why that's important, but I didn't think about it at the time.
Once all the sections were done, I set the bookcase back up. You can still see the three panels of the bookcase back, but the foil design reflects its pattern onto the top and sides of the shelves and reflects some light into the room. I'm all for reflecting light in here--I have black curtains, black furniture, and no overhead light (except the red hanging star lamp you can sort of see in some of the photos), so this room tends to be a bit dim. That's okay, though, since this is my media room--the dimness just helps make it feel cozy and warm!
I added the books and decorations back to the shelves and stepped back to admire my beautiful bookcase! I think the subtle pattern makes the whole thing look richer and less like the cheap thirty-dollar bookcase it is. I might add some more touches of wrapping paper to it at some point, but for now, I'm really liking this little transformation!