Please help in extracting ps2 files

[ActionHill]

Hello. I'm kinda new to the whole ps2 scene. I have a question about some of the file types I've been seeing on ps2 discs. For instance, I wanted to take my Capcom vs. SNK 2 original and change the music and sound effects and then burn it and play.

I knew it would be difficult and time consuming, but I was really confused when I found out that all the files on the disk are compressed into 5 big files in the "PS2" directory. They end in the extension ".AFS"

I decided to look around for programs that would extract this type of file. No luck. I remember having the same problem in looking at Guilty Gear XX when trying to make a rip of it so I could play it with the swap trick before I got my mod chip. That game had everything in one big .PCK file. I found out a LITTLE information on what that should be, and I found it was rooted in linux. Is this a common thing for PS2 to use linux files? None of the rip guides or rip packs that I found contained any information that helped me. Anyone who knows anything about .PCK or .AFS please help me out.