Default need help restoring Gear to stock firmware

Hi, I installed null on my Gear, but it gave me lot of problems so I decided to restore the stock firmware. I have done lot of searches, but since I am a newbie a didn't understand what to do. First i don't know where to get the ROM file. I found a thread listing all the stock ROMs for the various regions, but there are no download links, the author just says "you know where"... ehm I don't actually know where so I am totally confused. Plus, I don't actually know what to do with the ROM file once I download it.
Ok I know this could be a very noob question, but I am really confused, because all the guides are not so clear and sometimes they use some kind of coded language (is this cool?) and I can't get the meaning of any the expressions used, understanding anything. I just need to know what to download (just need a link) and how to flash it in order to restore my gear to stock ROM. Thanks for your patience, hope you can help.