Go to Eldin Volcano and choose Volcano Ascent as your landing destination. The place on which you play your harp is right next to you. Once the song is complete, enter the spirit realm.
At the start, walk out of the safe zone, wait for the Guardian to come a bit closer, then sprint up the path to get the tear. Go back a bit and into the tunnel to your right. When you exit go right again and pick up the tear that's located at the bottom of the vines. Climb back up and get the tear straight ahead, past the tunnel entrance.
Go back into the tunnel and jump into the air jet. Go south, and in the room with the guardian pick up the tear up on the ledge to your left side. Be careful to not touch any of the water as you slide down.
Stick to the right as you go and land on the small ledge near the bottom. Jump to the left using the two air jets and grab the tear. Now jump onto the path, between the two water patches and sprint up to grab the other tear.
When you slide back to the bottom follow the path, jump across the platform and drop down to the lower level on your left when you reach it. Sprint across the bridge, climb up and go right to grab another tear. Go back and sprint across the other bridge, but be careful not to run into the Watcher. Climb up the ledge on the left to reach the two platforms that lead to the tear sitting on top of the skull.
Jump back and climb up all the way to the top-most level. A tear is hovering just out of reach near a Light Fruit. Jump and grab the nearby rope - now you can grab the tear by swinging yourself towards it. Proceed along the top level now, past the Mogma house and the guardian, and grab the tear sitting on the small ledge straight ahead of you.
Jump down to the path below and head forward. When you reach the guardian you'll see a tear up ahead on a pillar, with a rope leading to it. To reach the rope you need to crawl through the hole slightly to your left. Once you have it, go back, and as you crawl out of the passage again, head right to grab tear #12.
The next part is tricky - head north, as you'd normally walk through Eldin Volcano - past the bridge patrolled by the Watcher, the across the other bridge on the right, up the vines and through the tunnel with the big air jet. This will lead you back to the very beginning on the silent realm. As you exit the tunnel, stick to the right side and go through the other passage. Jump over via the platform and grab the tear just up the slope. You should have enough time to get here before the Guardians wake up.
Do not sprint up the slope right away - sprint to the left, where you'll find another easy tear. Now in order to sprint up safely, you must not take a break, or the Watchers will see you. So sprint back to the right side of the silde, then sprint up, all while sticking to the right. Pick up the stamina fruit on your way and just jolt past the Watchers. Once you are up, go right and grab the last tear in the middle of the area. You could have gotten these three tears right at the start, but this way you end up near the beginning once you collect them all.
Make your way back to the enrance to finish the trial.
Back in the real world, head into the cave near the bird statue and up the big air jet. When you get up, go right and up the path to the edge above the small lava pit. Enter through the door and into the superheated Volcano Summit.
Head past the bird statue and drop into the wide open area. Go left, across the lava and out through the cave exit.
Scoop some water into two empty bottles then head back in. Go left up the path and into the new chamber. Stand in front of the frog head and pour the water on its tongue. In the next room pull yourself up to the vines on the left using the Clawshot, then pour the water down on the Frog's tongue from the ledge above.
After you reach the temple entrance you will find out that you need much more water for the final frog. Head to Faron Woods and choose Floria Waterfall as your landing spot. Talk to the Water Dragon, then head back to Eldin. You will now have to escort the robot to the summit, killing enemies to protect it as you go.
Be careful, the enemies will attack Scrapper. Once you reach the Volcano Summit be especially careful of the pack of Keese flying around, they can destroy him in seconds. Once you drop down to the wide open chamber you'll have to fight two Lizalfos. After that it's a clean stretch to the top.