(adsbygoogle = window.adsbygoogle || []).push({}); How do i start what do i do first?

First you would want to grab a PS3 on a custom firmware (CFW) also known as a jailbroken PS3. You can either grab one that is on 3.55 firmware and do it yourself or get one all ready to go for you.

Technically you don't even need to have a jailbroken PS3 to get your own mods. You can have mods for some of the old COD games, even in multiplayer even on a normal PS3 on official firmware. All you need to do is get yourself a recent/updated modded PS3 backup and restore your PS3 with that backup.

I'm not familiar on the rules on these forums regarding links but if you lookup PassiveModding on Youtube you can get a look at his video regarding his V12 backup