(adsbygoogle = window.adsbygoogle || []).push({}); Just wondering, if so, could you link me to the files, and a tutorial?

No there is no way out yet of modifying multiplayer without cfw.

What about if iinstall the eboot.binto my ps3 with filezilla? Will it work or i have to ftp it?
Cuz in modded patches of mw2 it would be possible to install and host withou jailbreak cuz there is ea metode tha install the patch without a file manager but after install u have to ftp it so its impossible to ftp without jb

Yh you need blackbox and you can only get it with a jailbroken ps3.If you know someone with a jailbroken ps3 theres a method to do it without your ps3 being on cfw.BUT it only works on mw2,cod4,cod5

I think you may be able to host xp lobbys with Red-Eye's mw3 save game editor not 100% sure but maybe.

back ups is the only way, but they are banned on this site

You can't data transfer a modded EBOOT so unless a method is found with editing a save, No, it's not possible.