Looking for some OS help.

I received a RG35XX pro as a gift (very cool!). They had a coworker make changes to it before gifting it to me. I know many will say it was the best thing for the system, I'm not arguing against that. I am just very much into things being as they came.

As far as what happened - they formatted the original SD card and loaded a different OS (KNULL Gladiator II). They made it a two-card system. I want to go back to the way it came from the factory. Is there someone that can help walk me through getting the original OS back on it as it came from the factory?

Since all the games were moved to a second SD card, do they have to stay there?

Again, I know many will prefer the way it is now, but that's just not me.

Thanks in advance for any help given.