At first, you should get to Frostwolf Orcs - Honored,then you can exchange Permanent Frost Essence from Vendor: Beska Redtusk in Warspear by spending 1000 gold.
1.You will get Permanent Frost Essence.
2.You need to provide your account.
3.Your character needs to be lvl 50.
4.Estimated time: 1-2days.