Can anyone get their digital copy codes from LOTR extended blu-ray to work on iTunes Mac?

Bought LOTR extended edition combo pack back when they first came out, but never used the digital copy codes. Now my 13 year old wants to get them on his iPad, but the codes appear to be expired (6/26/12). I see talk online about WB extending the expiration of codes, but I still can't seem to figure out how to get these to work. Can anyone help?