--What you need--

1 CFW PS3
1 OFW PS3 (Both PS3's need to be on the same FW to be able to File Transfer!)
A demo of the game you wish to backup
Comgenie's Awesome File Manager
multiMAN

This instructions are for BO1 but they should serve as PoC

1. On your CFW PS3 Install your demo & backup the full game to the HDD

2. Open CAFM & on the left side go to /dev_hdd0/game/*game-demo*/PS3_GAME/
& delete the following: ICON0.PNG,PIC1.PNG PARAM.SFO

3. Open CAFM & on the left side go to /dev_hdd0/GAMES/*full-game*/PS3_GAME
on the right side open /dev_hdd0/game/*game-demo*/PS3_GAME
3b.Copy (or move) these files: ICON0.PNG,PIC1.PNG & PARAM.SFO

4.Now on the left side go to /dev_hdd0/GAMES/*full-game*/PS3_GAME/USRDIR/
on the right side navigate to /dev_hdd0/game/*game-demo*/USRDIR/

5.MOVE (not copy) all of the files from the left to the right
(Move all of *full-game* USRDIR'S Contents to *game-demo's* USRDIR)

THE ONLY FILE THAT YOU SHOULD NOT MOVE OR COPY IS THE EBOOT.BIN

6.Check that the game was correctly transferred by booting it on the XMB

7.File transfer to OFW PS3!!

I don't know why this works but it only works on games which have a demo available just delete the old "XMB" files
(ICON0 PIC1 PARAM) & then transfer everything BUT the EBOOT to the demo & it will boot as the full game

--If you want to update to 1.XX then:

1. On your CFW PS3 Install the pkg update

2. Open CAFM & file transfer every file to their respective direcctories BUT EBOOT.BIN
(e.g. /dev_hdd/.../.../*fullgame-update*/ to /dev_hdd0/.../.../*game-demo*/ & it will work)

--The black ops demo has online functionalities disabled
(if you go to Zombies>PlaystationNetwork it won't do anything)
but there is a dvar that can activate that (i think it's: set xblive_connection "1")
for this you have to mod your savedata & also mod your EBOOT since the modded savedatas have been patched & you will need bypass.

I came across this while trying to mod Black Ops 1 for Zombies but my CFW doesn't have a BD Drive
(i had to download COBO & ftp to PS3) but then multiMAN wouldn't boot it so - i tried EVERYTHING to make it boot & you know what IT FUCKING BOOTED (but i still couldn't mod BO1...)