When you're an adult warp to the Desert Collosus. Go straight past the Spirit Temple and you should see a dried up pond. Go left or right( I'm not exactly sure which way) and on one aide you should see two palm trees right next to each other. Go in the middle of them and you will see a crack in the wall. Put a bomb there and go in. Play Zelda's Lullaby on the Triforce and the fairy will come out. Nayru's Love put's half a rupee around you and this makes you invulnerable but it will take up magic from your meter so make sure you have the double magic meter.