Question [Q] Need Modem firmware for unlocking SGH-T999 on 4.1.2


I am a noob and trying to unlock SGH-T999 currently on 4.1.2 . Reading all forums, I learned that I have to downgrade to 4.1.1 . Also I read that I need to downgrade the modem , unlock , then upgrade the modem. I also managed to root the phone.

My problem is locating the files, everywhere I find is full spam and etc including Sammobile

I appreciate if someone can provide me a link that I can find the two modems I need.

Thank you in advance.