How to Put CSO/ISO Games onto a PSP

1
Download and install the PSP ISO Compressor (see Resources). Turn on your PSP that is running custom firmware. Press "Select," and you will be presented with the VSH menu. Navigate down to "USB Device" and change it to "UMD Disc." Insert your game into the PSP. Attach the USB cable to the top of it. Plug the PSP into your computer, and it will automatically connect.
2
On your computer, select "View Files" when you are presented with an autoplay window. On your computer, another window appears with an ISO file in it. Copy and paste the ISO file to your desktop. Disconnect your PSP from your computer.
3
Open the PSP ISO Compressor program. On the left, select the "Compress ISO->CSO" option. On the right, select the input file(s) button, and select the ISO file you just copied to your desktop. Select "Compress," and your ISO will be compressed into CSO format and saved to your desktop.
4
On your PSP, go back to the VSH menu and change "USB Device" back to "Memory Stick." This is done by moving your cursor down the VSH menu, highlighting "USB Device" and pressing the left arrow on the analog stick. Stop when it says "Memory Stick." Plug your PSP back into the computer.
5
View the files on you PSP's memory stick. There will be a folder named ''ISO." Simply copy and paste the CSO into this folder, disconnect your PSP from the computer and navigate to your game from the PSP's menu. Select it and play.