In case someone doesn't know RE You'd better watch-out (spoiler)
On the 2nd highest balcony area - you can climb-up the wall to the snow-covered roof. Sometimes you have to wait like 5-8 mins in order to not be seen since all guards are so addicted to cigs. lol I climb-up there and snipe the old guy. Then I drop a bomb in the hottub and then snipe guards till I'm out of bullets. They never have seen me!