You will need :
Blackbox FTP
Sen enabler/disabler
And mw3 update pkg files
For mw3 you will have to download update 19,20,21,22,23 if you don't no what they are, look it up on ngu everything else you need to mod is here on the site eg eboots and stuff
For mw2 just run black box on your ps3 then open FileZilla on your laptop put long code on your black box into the box at the top left of FileZilla and the username is ftdp12345 you don't need a password click connect , find your bles code for mw2 open it up go to USRDIR and drag and drop your patch_fp.ff onto the patch_mp.ff file on FileZilla close down FileZilla then on your ps3 go to network settings keep everything the same and when you get to proxy server go the use and put in this code 210.101.131.231 and your port will stay the same 8080 then now you have bypassed mw2 and will be able to host CL.
Hope this helped you any further questions just pm me.