Where are levels 5 and 6 in Glen's 4th quest

Level 5: Go to where you found Level 8 in the First Quest. Go north and west. Then burn one of the trees.

Level 6: You will find the Raft in Level 5. Use it to get to the cave where you found a free Heart Container in the original Zelda (both quests). In this quest, that is Level 6.