Quite self explanatory, this one is.
-The AK47 is your friend. You will love it, and it will love you.
-Running past enemies will almost always happen. Don't waste time trying to kill everyone.
-At the same time, be smart and use cover. Dying will just make life harder.
-Don't worry about secondary objectives, all you should be focussing on is hauling ass.
-When you try to use the elevator, but it stalls: Don't forget you can vault from the top floor to the bottom. This will save you some time.
Honestly, this isn't that difficult; I got it on my first try, with 3 minutes to spare.
Just be smart and keep your wits about you, and you'll be fine.
If you downvote this solution, tell me why so I can improve it.