If you have a single deckplate the pedals will have to be removed from the arms before you can remove the deckplate. If you have two deckplates, only the clutch pedal has to be removed from the arm.
Make sure the holes on the arm and shaft are in alignment. Some people will insert a smaller split pin inside the larger one and index the splits 180 degrees apart. Personally, I prefer the coiled pins.
I think you got this.