Travel to the east most tower.

On the way up to the tower there was an unusual amount of guards along the path. One of them comes out over to you.

"What right do you have up here? This is a restricted area!"

"I have special orders." you tell him.

"What orders?"

"Stilgard, show him our orders." you say.

The guard turns to face Stilgard.

"This is just a gate pass."

With the guard's back expose you knock him over the head. Quickly changing into the guard's uniform.

"Stilgard wait here. I will get the Eye of Everlore." you say.

Racing up the stairway you find two more guards outside the treasure room.

Kill the guards before they expect anything.

Talk your way through them.