What are heck are you smoking ?
I installed almost all the games I threw at my PS3 except NFS HP.
And yes, this is a wee bit complicated, but this is what you get when you want things for free. Don't expect people to spoon feed you. You need to work on it, read the tutorials and get an understanding of how it works.
At the end of the day, it just works. For Slim and Super Slim models, there was no hope. These guys made it happen. It was difficuilt, but they did it. So, if they put in so much effort, can't we do our bit ?
A Word of Advise : Use .pkg/.rap file method of installing games most of the time. ISOs and converted game have been reported to give black screen. Each and every .pkg game that I have installed (except NFS HP) have worked flawlessly.
Get your copy of COD Ghost as a PSN store .pkg file type. Get it's .rap file. Follow the tutorial and install the game. Activate it and then play.
I have done this and it works.
On a side note : The game is kinda shitty. Get COD MW3 instead. Campaign and frame rates are excellent
Most people who did install a PSP game did indeed report black screen problem.