Board Thread:Skyrim/@comment-124.184.73.75-20140111003957/@comment-10906938-20140112021009

Once you start sneaking in, there is a room on the left side of the first corridor. That room seems like a dtorage area (if my memory isn't distorted) and has some Thalmor items inside. Those might help, at least until you can loot from the Thalmor you'll have to kill somehow.