you knock out the security downstairs, with a "story" ...like, you inject them, then you ask permission by radio, to security guy himself goes up...push him inside, clearence is given upstairs, you hold on the the elevator with a paper magazine, the doors open again, you get inside, clearence was already given electronic, elevator goes up, they will try to stop it at some floor. Here's the tricky, for the 4 biggest security companies ( OTIS, Mitsubishi Electric and FUJITEC) try this, double press the floor button (the one you want) or press it 5 times. two ways not let open the door while you're going up, you press at the same time, the floor buttom ddor close and the floor number...or you use your snickers like on the image. (no source, i'm sorry)