Board Thread:Questions and Answers/@comment-28905095-20170216140705/@comment-28272355-20170220091404

Herobrine is actually close to the method I found in slaying the Wither.

All you have to do is to mine upwards till you reach the upper bedrock layer. Once you find the bedrock layer, mine three blocks high and a wide room for it. If you find a bedrock platform which is two blocks away from the original bedrock layer, this will advance you to the next step, especially if the platform is 3x3. Spawn the Wither by building it horizontally, this will spawn the Wither. Once the Wither proceeds to its first explosion, it will suffocate on the bedrock layer, but will still try to get out by blasting wither skulls so keep the room wide. Once it dies, you can obtain the Nether Skull.

This method works for PC and I haven't really tested it yet on the PE.