For those toying with the idea of doing it yourself I'll throw a few keywords in to help you out (bit cryptic but I'm not going to give all the info out.) Not even if Scope puts a bullet in my arse!
ODIN Multi Downloader 4.252
USB Cable
XXJPM One Package
XXJG3 (NOT one package - in case you wish to roll back)
BIG NOTE: NEVER - I MEAN NEVER FLASH BOOTLOADER OR SBL.bin FILE - You WILL NOT get it replaced (You have a 99% chance of erasing IMEI and rendering the phone useless if you do this without the security kit.)
Lets see what ideas you can come up with after having a "google" or "yahoo" or "ask jeeves" even!