Check out her instructions here (because unlike some other bloggers, I truly believe in giving credit where credit is due and this was NOT my invention).
Here's what I learned and I hope may help you in recreating this project...
Instead of tracing your computer screen (yes, she actually advises doing that), if you're lucky enough to have one, use your Silhouette Cameo/Portrait to cut out the letters with standard 12x12 scrapbook paper. I used the font: Bready Regular Demo which can be found and downloaded for free here and I enlarged it to 900 font size. Please note that you may have to weld certain letters - for example 'M'. I did everything in capitals because I didn't want to have to deal with the dot over the 'i'.
Also, don't worry about using cardboard for the letters, just pick up a few extra pieces of white poster board. So much easier to cut than cardboard! Furthermore, if you have the smarts and ability to use your Cameo/Portrait, go ahead and use it for this as well. I tried but the poster board kept slipping around and rather than throw the thing out the window, I decided to trace around the scrapbook paper letters. I then cut slightly inside the lines because you want to make sure that the poster board doesn't poke out from behind the pretty paper.
Other than that, I'd say the tutorial is pretty self-explanatory. However, I will not gloss over the fact that it is super, duper annoying and irritating to determine where to place the 100 bulbs. There's no mathematical equation that can be used because each letter is a different size. So, I just had 100 small square pieces of paper cut out using my Cameo and then placed them around the letters until it looked about right. The problem is that they're so small, that you start losing them and then have to count over and over and over again until you're sure you have exactly 100.
I used the same lights she recommends which can be purchased on amazon.com here. Call me a helicopter mom, but I wanted to make sure that the poster board didn't catch on fire in my sweet girls bedroom right above her bed.
Peaches McGee loves her lights and will show just about anyone willing to go up to her bedroom. She even erased the next 30 minutes of potentially irritating behavior by saying, "Thank you momma! I love how you decorated my room."