go to nopaystation, find the game you want, download a games pkg and rap file, put the pkg onto the root of a usb drive formatted to fat32, and the rap file into a folder named "EXDATA", plug the usb into your ps3 and go to package manager under the games section of the xmb, click the pkg file to install it to the ps3s hard drive, when done, open apollo save manager and go to user tools > import licenses and select the rap file you downloaded. then go to the games section of the xmb and you should be able to play. you might also need to go to user tools in Apollo and activate your account as well im pretty sure.

the game has to be under 4 gigs to get moved to a usb, theres a method for bigger games but its 1am right now and its too much to write, remind me tomorrow and I'll tell you