1) dl any rom
2) put it into a folder and name it
3) 7z the file
4) you'll see a file names signed_RUU.nbh
5) r click rename JUST THE "signed_RUU" NOT THE .nbh
6) rename to RHODIMG in caps----the .nbh extension should still be in place.
7) make sure your SD card is FAT32 formatted
r click copy the RHODIMG.nbh file and paste to the root of your SD card---with no other executable files on the root
9) pull the battery, re-insert, vol down then power.
You'll go into bootloader and this flashes from SD--I always leave a stock rom renamed RHODIMG.nbh in a file for emergencies if I have to flash stock on the fly.
if for some reason this does not work,
pull the SD, pull the batti, vol down then power to get into bootloader---connect your phone to the computer and listen for the connect "sound" Find the dl file, the rom you want, and the "rom update utility" double click and you should flash from computer without being active sync'd