He did this in broad daylight. The guns were disguised in cases. He used the service elevator with staff help. In one case the staff helped move his guns on a rack.

If he leaves the guns in the cases it just looks like he has a lot of luggage. He had a huge suite. If it didn't look odd to them in the first place I can't imagine how it would in retrospect:

https://www.youtube.com/watch?v=uci5Ar2HFr0