So, you bought a new HTC Evo 3D, got to home to try out and realised it's locked to Sprint ? I did too and got furious. That's when I decided to flash it to Boost Mobile.
It took me a while but I finally managed to do it. I've created a 9 page PDF which teaches you all the details, on how to successfully flash your Sprint HTC Evo 3D to Boost Mobile.
Everything is explained extremely indepth in the ebook and links to each tool will be provided aswell. The flashing itself shouldn't take more than 5 minutes. You can find the download link below.