Allow the frozen puff pastry to defrost in the fridge for several hours. If you are really short on time, you can defrost it at room temperature on a lightly floured surface, carefully flipping a few times as it defrosts.
Don’t let the pastry become soft because that means the butter is getting soft and you will start to lose the flakiness that puff pastry in known for. If your pastry gets too soft, return it to the fridge until it becomes firm again.
Since this recipe uses both sheets of puff pastry, leave one sheet in the fridge until you are ready to work with it. Likewise, it makes it rather simple to cut this recipe in half if you just want to use one sheet and make four danishes.