Resetting specific config

I installed RetroArch on my jailbroken iPhone 5S with iOS 7.0.4 and I used it to play N64 games. Two days ago I downloaded Conker’s Bad Fur Day and it was so slow that I tried changing the Plugin to Rice and closed the game. When I tried to open the game RetroArch suddenly closed, and it’s the same for every N64 game. Problem is, that menu can only be open when a game is already running, and every time I try to open any N64 game it just quits. I want to know if there’s a way to reset all my settings, or to know where (directory) the settings are stored to change it manually. I tried deleting RetroArch and installing it again (via Cydia) but it keeps all my previous settings. Please, it would be really helpful, since I miss playing those games like I did before (Using my DS3 and pluging my iPhone to my TV =( )

Nevermind. I found a workaround. I loaded a non-N64-game with Mupen64 core, and since it couldn’t load, plugins were not initiated. As it remaied on a black screen I could enter Core Config to set GFX plugin back to Auto