Right at the beginning of the game at the Avatars house, if you go outside to the hopscotch court you will see a rock. Climb up onto the rock and jump onto the frame of the dummy. When onto the dummy (can take practise) aim the crosshair above the fence and towards the tree on the other side of the fence. Jump, and you should be on the other side. Now that you're there walk around the tree to its far side. Look down at the base where the glass rises up and click around a bit. This will activate the teleporters. The ones closest to the fence change your armour while the further ones take you to major plot points.
(Unfortunately, while you can keep the armour, I have not found a way to get magic whilst playing through this way, and keep the armour.)