Instructions
Visit the Eastern Hills. Fuse Kinstones with the farmer named Eenie by pressing "L" when you are close to him, and select a matching Kinstone piece and press "A." The Goron from Lon Lon Ranch will then dig into the Goron Cave.
Visit the top of Mt. Crenel. Proceed down a ladder on the left. Equip your Mole Mitts and dig through the left-most cave by pressing "R." Continue digging until you reach the top-right corner of the cave. Clear the ground with the Mole Mitts and a symbol will appear. Fuse Kinstones with the symbol. A Goron will appear in Goron Cave.
Go back to Eenie and Meenie's farm. Dig into the cave using the Mole Mitts at the top-left of the farm. Dig through the cave until you reach the top-right corner. Fuse Kinstones with the symbol on the wall. Another Goron will appear in Goron Cave.
Visit Minish Woods. Dig into a cave southwest of Syrup's hut; keeping digging until you reach the top-right corner. Fuse Kinstones with another symbol that's on the wall, and another Goron will appear in Goron Cave.
Go to Tribly Highland and dig into the first cave after crossing the first bridge. Dig to the furthest wall and fuse Kinstones with another symbol, which makes another Goron appear in Goron Cave.
Equip Roc's cape and travel to Lake Hylia. Jump from island to island with Roc's cape, until you reach the northernmost cave. Dig into the cave, turn left and take the first downward turn. Keep digging through the cave until you reach the wall with the mysterious symbol on it. Fuse Kinstones with the symbol, allowing the last Goron to appear in Goron Cave.
Go to Goron Cave located at the bottom left of Lon Lon Ranch. Continue through the cave and across a platform. Open the chest to receive your reward.