Noeman do not condone the illegal use of PS1 Eboots. We are assuming that you own the original games.
1. Make sure you have 3.40oe-a firmware, you can check in your PSP’s system settings tab then system information. A guide to installing the 3.40 oe-a firmware can be found Here. If you have any firmware other than 3.40 oe-a or 1.50 you will need to downgrade your PSP, a guide can be found Here.
Download the PS1 Eboot/s that you want (recommended :: Master Zone , you need to go to the ‘PS1 eboot’ thread) You should get two folders, one with a % and one without, if so, put both of these folders in the (your psp)>PSP>GAME folder of your PSP. If you only get an Eboot.PBP file, you need to make a folder with the games name and put it in the GAME folder in your PSP (as shown above).
2. You should now be able to access your game/s by going to the Game tab on your PSP then ‘memory stick‘, if not, you have either put the files in the wrong place or the Eboot is not compatible with 3.40 oe-a.