Well, I figured this out while playing AV and trying to cap the FW RH.
There is a pile of snow directly behind the hut with a pole near it...
step on the pile of snow, try to wall jump up it farther, step on the top of the poll, jump on top of the hut and its done
You'll evade the guards and I doubt others will figure out how to get up
Course, ranged classes can kill you but if youre a mage/lock you can kill them first
Great for capping it if youre alliance or taking it back if youre horde.
Solera