Use the Divination Scryer in the heart of the Great Ossuary's basement in the Scholomance. Doing so will bring forth the spirits you must judge. Defeating these spirits will summon forth Death Knight Darkreaver. Defeat him and reclaim the lost soul of the fallen charger.
Give the Charger's Redeemed Soul and the Blessed Enchanted Barding to Darkreaver's Fallen Charger.
Take this satchel - in it are the items you will need for your task.
Use the divination scryer in the heart of the Great Ossuary's basement to bring forth accursed spirits that must be judged. Use your judgments wisely during this trial - they will prove more potent than you realize. After the spirits, the death knight will appear; defeat him and reclaim the lost soul of the charger. Only then <name>, will you be able to redeem it and place your barding upon your new steed!
A glimmer of life - long vacant from the poor beast - shines in its eyes as you hand its judged soul back to it. You feel a holy rush of power surge around you as you place the barding on its back, having judged the charger redeemed. The charger nuzzles your hand as the burdens of the past are lifted from the beast. You now feel as though you could call upon this beast to serve as your steed, should the need arise.
You have claimed your epic charger, <class>! Congratulations!