It's not entirely a complex process. But it is kind of long though.
Here goes.

Requirements

Pc or a good smartphone

Your game in Iso format

Your Sd card formated in fat32 format

Openps2loader.elf latest version (this is optional, it is however advised that you update you opl otherwise you might run into compatibility issues when trying to launch games)

Procedure:

Download your desired game online. Visit coolrom or other iso sharing sites for your game. Just google "crash nitro cart ps2 iso" you'll get links to download from. Some of the isos are archived so you'll have to decompress them before you can get your iso game.

Google and download the latest version of opl you can find. Try googling "opl latest version download". After download, extract the archive and you'll get a file name with a ".elf" extension. Move or copy this file to your flash or sdcard that'll contain your game.

Create a folder named "DVD" in the flash or sd card. Now copy your game in iso format to into that folder.
Next plug in the flash and boot up your ps2. Since it's already hacked youll see the freemcboot splash screen.

Once you boot up your ps2 hold "R1" when you see the fmcb splashscreen. Ulaunchelf will boot. Now with it navigate to "mass" which is your sd card, locate the ".elf", highlight it, press "R1" to bring up option, chose copy, navigate back to home directory, open mc1, open "apps" folder, press "R1" again and then select paste. Now you've copied opl to your fmcb memory card.

To be continued...

Oluwaseunsodiq:
It's not entirely a complex process. But it is kind of long though.
Here goes.

Requirements

Pc or a good smartphone

Your game in Iso format

Your Sd card formated in fat32 format

Openps2loader.elf latest version (this is optional, it is however advised that you update you opl otherwise you might run into compatibility issues when trying to launch games)

Procedure:

Download your desired game online. Visit coolrom or other iso sharing sites for your game. Just google "crash nitro cart ps2 iso" you'll get links to download from. Some of the isos are archived so you'll have to decompress them before you can get your iso game.

Google and download the latest version of opl you can find. Try googling "opl latest version download". After download, extract the archive and you'll get a file name with a ".elf" extension. Move or copy this file to your flash or sdcard that'll contain your game.

Create a folder named "DVD" in the flash or sd card. Now copy your game in iso format to into that folder.
Next plug in the flash and boot up your ps2. Since it's already hacked youll see the freemcboot splash screen.

Once you boot up your ps2 hold "R1" when you see the fmcb splashscreen. Ulaunchelf will boot. Now with it navigate to "mass" which is your sd card, locate the ".elf", highlight it, press "R1" to bring up option, chose copy, navigate back to home directory, open mc1, open "apps" folder, press "R1" again and then select paste. Now you've copied opl to your fmcb memory card.

To be continued...

bros I'm feelin' ur tut. abeg finish am lah