Seize the glowing sword at the top of the spiral stairs in Sturmfeste ( -150, 6, -96 ) /waypoint -150, 6, -96. An Inert Bone Bladed Claymore will appear in your inventory. Examine it to be offered the quest.
Kill Opalla, a level 42 ^^^ heroic gnoll shaman, inside Blackburrow. You can find Opalla directly south of the bridge, in the farthest room ( -24, -16, 83 ) /waypoint -24, -16, 83. He will spawn and attack you as soon as you enter the room.
Examine the sword.
Slay Redak, the Troll Warrior, a level 44 ^^^ heroic mob located in the chapel in Stormhold ( 72, -16, -25 ) /waypoint 72, -16, -25. Easiest way to get to the chapel is to go down the spiral staircase, go down the hall to the atrium and enter the door to the left of you, There will be a "pond" in front of you, take the path to the right and follow it down until you are in the room with the cavaliers. Go up the staircase and follow the hall that wraps around the room to a door that will be on your right.
Examine the sword again.
Re-forge the hilt and bone blade and make it one again.
Go to Runnyeye and head down the path just past the bridge until you come across the first room with goblins past the archway, there will be another room with more goblins. Once you enter the room to the left there will be a small alcove and inside will be a forge and a anvil sitting in front of the forge. Inspect the anvil to reforge the blade. ( -10, 1, 5 ) /waypoint -10, 1, 5
Examine the sword again. To get your sword you will need to slay 1,000 sentient beings.
This means any non-animal (humanoid). Skeletons work fine for this.The Graveyard zone next to The Commonlands, The Miror in Thundering Steppes, the Ruins of Caltorsis in Antonica, Blackburrow in Antonica or the Sprawl or the Ruins in Freeport are good places to do this if you don't mind the lack of XP. Orcs and goblins work as well, so feel free to visit Zek, Lavastorm or the Sinking Sands for some good XP (if you're not high enough to solo these zones, by all means go with a group). Lizardmen such as found in Feerrott are fine also. There is also a small island just off the shore in Antonica north of the Oracle Tower which has fast respawn (nearly as fast as you can kill them).
You may wish to stay in stormhold, for at least part, and simultaneously do Berik's Revenge quest, which requires killing 100 undead.
Examine the sword again.
Kill Gynok Moltar, the first wielder of the claymore. He is a level 47^^^ heroic mob, that spawns when you enter the room where you first grabed the Claymore on top of the spiral staircase in Stormhold.
NOTE: You can now obtain the Electrified Bone Bladed Claymore after you've finished the original quest. By right-clicking on the forge in Runnyeye with both the standard Bone Bladed Claymore and Berik, Sword of Thunder in your inventory (but not equipped), you can choose to "Break Berik over the forge." Berik and the BBC will be removed from your inventory and you will receive the Electrified Bone Bladed Claymore. If you choose to do this, you cannot change the EBBC back to the other two swords, so please be sure of your decision.