Resident Evil 3's new demo which is available everywhere now only has one safe in it to crack open, but it's got a worthwhile prize inside if you know how to unlock it. Inside of the safe found in the short but tense demo is an attachment for your handgun, the primary weapon you'll be using to fend off zombies throughout the preview. The attachment is a dot sight which should improve your aim when landing those much-needed headshots, so if you want to be as equipped as possible in the demo, you're going to need to know how to open that safe.
To start, you first have to find the safe. Once you get into the open city area where you can see Moon's Donuts, you should see some stairs towards the right leading to the upper level of the buildings. Take those stairs and you'll end up in a storage room where a man lies dead on the floor. He's not a zombie – though you will be encountering zombies in the room and on the way – and next to him is a safe.
We don't know the combination yet, but by investigating the man's body, we have a clue as to where to find it. The man ran the pharmacy store that's conveniently located nearby and thought a lot about a hair growth product from Umbrella Corp. called Aqua Cure. His note implies that the code for the safe has to do with that product since he references the "Aqua Cure queen."
To find that queen, head over to the Redstone Pharmacy that's nearby while avoiding or killing any zombies you might come across. Inside, you'll find a poster of the Aqua Cure queen hanging on the wall with a phone number on the bottom of it. The circled numbers are nine, one, and eight, and those are exactly what you need to open the safe.
Return to the safe while staying safe yourself and enter the numbers in the order left, right, left. Confirm the code, and assuming you did it right, the safe will pop open to yield its prize.
Just because you have the gun sight doesn't mean it works automatically though. Go into your inventory and combine the sight with your handgun to use it. It'll help when you're trying to land headshots against lurching zombies, and you're going to need it whenever you go up against Nemesis.