Dragon Slayer

Talk to Oziach in the house directly north of the Edgeville lodestone.

Go back to the Guildmaster and talk about the map pieces to get the key, about protection against dragon breath, and about buying a boat.

Go to Melzar's Maze by entering the tower entrance north-west of Rimmington.

Enter the door with the maze key.

Kill the small zombie rat with the long tail, pick up the red key and use it on the north-west door, then go up the ladder.

Kill the thin hooded ghost with the patterned robe to receive the orange key, go through the door second from the north on the eastern wall and climb the ladder.

Kill the skeleton with the small round shield and pick up the yellow key. Use the key on the south-western most door and climb down until you get to the zombies.

Kill the zombies. One of them will drop a blue key. Pass through the blue door.

Kill Melzar the Mad, pick up the magenta key and pass through the magenta coloured door.

Kill the lesser demon, pick up the green key, and go through the green door.

Open the chest and search it for the map part.

Note: Make sure you finish the dialogue, or you will not receive the map part.

Talk to the Oracle on Ice Mountain.

Travel south into the dwarven mines. Find the room with a sealed door in the north-eastern area of the mine and use all the items on the "Magic door". (Unfired bowl, wizard's mind bomb, lobster pot or a crayfish cage, and silk)

Open the chest in the room and search for the second map part after opening. You need to click again to search after the dialogue, it does not automatically loot or search.

Head to Port Sarim Jail and talk to Wormbrain in the cell.

You may need to speak with the Guild Master at this point before you can attack Wormbrain.

There are two ways to obtain the third map part:

Talk to Wormbrain and pay him 10,000 coins for the map part.

Attack Wormbrain and use the loot interface or Telekinetic Grab to get the map part that he drops. You may need to drop an item in order for the loot interface to open.

Use a map part on any one of the other parts to form the complete Crandor map.

Talk to Duke Horacio on the first floor of Lumbridge Castle.

You can also buy an anti-dragon shield from the Grand Exchange to skip this step entirely.

If the dialogue option for the anti-dragon shield doesn't appear, you need to talk to the Guildmaster about protection from dragon fire

If you haven't already, ask the Guildmaster in the Champions' Guild about the boat and the captain of the ship.

In Port Sarim, buy the ship Lady Lumbridge from Klarense, by the Void knight Squire.

Repair the damaged deck of the ship.

Go to Draynor Village. In the house north-east of the bank talk to Ned.

Prepare the battle against Elvarg.

Melee is recommended due to how hit chances are calculated.

Players with level 37 Prayer can use Protect from Magic.

Board your ship and talk to Ned. Tell him you're ready to sail to Crandor Isle.

After crashing on the island, follow the light grey path around and up to the top of the mountain. Climb down the hole.

Move past the skeletons until you see Elvarg behind a short wall of spikes protruding from the ground on the east.

Before you climb over to Elvarg its advisable to open the shortcut in the wall south of the short wall.

Climb over it and kill Elvarg.

Wear your dragonfire protection before hopping over, or your stats will get drained resulting most likely in a failed kill.

If you leave Crandor before killing Elvarg or opening the shortcut, you will need 3 planks and 90 steel nails to repair the ship to get back.

Take Elvarg's head to Oziach in Edgeville.

Quest complete!