Route doesn't really change compared to 3 star. The idea is to use the windows on the ride up to clear the interior, the doors to clear going down on the exterior, and deliberately getting close enough to hit the doors on the dark room up and right from the basement elevator to get the suits to come out for you.

Bomb on the elevator is destroyed because it will cause both doors to open, causing enemies to the left to be in unexpected places. Sniping Dick (yes, that's his name) at the very end increases the chance a single shot with killing spree will clear the hostages.

Also some good cover stepping in the bottom right corner of the mission.