Summon Thalassian Charger

Courtesy of Tenbatsu of the guild Band of Brothers:

The level 60 Blood Elf paladin mount quest is the following:
1) Talk to the Silvermoon trainer which gives you a quest to talk to a blood knight downstairs in the paladin area. She wants you to bring her 40x Runecloth, 10x Sungrass, 6x Arcanite Bar, 5x Dark Rune and 150g.

2) When this is complete she requests that you kill 15 Scourge Siege Engineers and 3 Meat Wagons. These are located in the north of EPL near the entrance to Ghostlands.

3) Once this is turned in the quest giver asks you to loot a vial of Holy Water from the library wing of the Abbey in Tyr’s Hand (it’s a little dish on a table) and return to her.

4) She then asks you to purchase a Crepuscular Powder (150g) from the poison vendor and an Arcane Catalyst (45g) item from the reagent vendor, both of which are located in Silvermoon and bring them back to her.

5) Finally you are given the task of extinguishing the Eternal Flame in the chapel in Stratholme (the church just inside the back door entrance, you only have to kill 2-3 pulls, the Eternal Flame is on the table). When you do this the Paladin quest giver (the medallion quest, Aurrius) who is normally in the chapel attacks you and is easily defeated. Next 6 paladins ride up and you have to fight them. They were extremely easy (our group didn’t even heal) and once defeated the quest is complete and you can turn it in for both the epic mount ability (includes the training) and the Silvermoon (Blood Knight) tabard!

Step 4 of your list also requires 1x Pristine Black Diamond and 1x Azerothian Diamond.

Here is the quest series:
http://www.wowhead.com/?quest=9721