Just put that in the root of your SD card, reboot to bootloader, and it should do the rest.
Then, after that's flashed, go into recovery (it should say that it's in safe mode), do the "wipe everything except sd card", reboot recovery again, then flash the new rom.
There's a big difference. Texts and mms seem to send and receive faster, calls seem to connect faster, etc etc.
Even if you originally did what Leslie Ann said in the thread The "Fix everything by turning your phone into an Evo 3d" thread , this is a newer radio then what was posted.
(Thanks to [Link] Radios for S-off for the link)
Just wondering, if I am just updating your rom and flashing this new radio, can I just do a dirty wipe (clear davilik and caches) instead of wiping everything? It takes me quite a while to install everything and redo the settings if I have to do a full wipe.