There is a white X next to the door. I punched it, but it still didn't work. What can I do?
Once the Jewelry Store is open (the lights are on and the 'closed' sign is off) walk up to one of the two 'X's on the ground (it is more likely that the X with the most players on it will work).
A laser cutter will appear and begin to slice through the glass, which takes about two seconds. After a short gap appears, crawl through the slot and enter the Store.