You can get Glory of the Pandaria Raider by completing of Pandaria raid achievements in amount of 29:
Must Love Dogs;
Sorry, Were You Looking For This?;
Like an Arrow to the Face;
I Heard You Like Amber…;
Who’s Got Two Green Thumbs?;
Heroic: Stone Guard;
Heroic: Gara’jal the Spiritbinder;
Heroic: Imperial Vizier Zor’lok;
Heroic: Amber-Shaper Un’sok;
Heroic: Protectors of the Endless;
Heroic: Lei Shi;
Anything You Can Go, I Can Do Better…; Straight Six; Candle in the Wind;Less Than Three;
Timing Is Everything;
Face Clutchers;The Mind Killer;
Heroic: Feng the Accursed;
Heroic: Four Kings;
Heroic: Will of the Emperor;
Heroic: Blade Lord Ta’yak;
Heroic: Wind Lord Mel’jarak;
Heroic: Grand Empress Shek’zeer;
With Glory of the Pandaria Raider achievement you receive also Reins of the Heavenly Crimson Cloud Serpent.
Here you can buy "Glory of the Pandaria Raider" for EU or US Servers. Also you'll get guide for completing "Glory of the Pandaria Raider" and can help your friends with these hard quests.
It is a rather harder that it may seem, and we are there for you to do your game process easier.