Enter the shrine by placing your Sheikah Slate on the pedestal. It will open up and you can go inside to a small circular platform. Press “travel” here to enter.
Next, there will be a short introduction to the trial. You’ll see another Sheikah pedestal over in the left corner. Go over to it and place the Sheikah Slate there. It will distill a new rune for you — the magnesis rune.
Turn around and look on the ground. There are two large metal plates. Use the new rune ability to grab these plates and move them out of the way. Underneath you’ll find a large hole–go through here.
You’ll find yourself in a room with a wall of cube blocks. One is made of metal. Use Magnesis to pull it out of the wall, then jump or climb through. Behind this is a metal enemy. Defeat it.
Next cross the metal plate bridge to the middle platform. Use Magnesis to move it and place it as a bridge to the next platform.
Look around. Next to this platform high above there is a treasure chest. To get it, use Magnesis to wedge the plate into a position where you can reach it. Return to the platform.
Pull the large metal doors open with Magnesis. Approach the large blue cube and activate it to speak with the monk. He will give you your first Spirit Orb.