Help, even though I'm an most likely idiot

[9Blades]

So I used to play around with customs on Brawl. I eventually decided to install Project M because I wanted to see how it compared. I enjoyed it but kinda wanted to still be able to use the customs back on Brawl. Found out that even if I remove everything from my SD card and add back the Brawl stuff, it would revert back to that. Nope.
Tried using a USB stick that didn't have any Smash stuff on it, nope, still for some reason loaded PM.
Is it possible to go back to regular Brawl? Or is like the disk permanently Project M now?

 

[Narpas_sword]

pm doesnt alter the disc.

take out the SD card.