In Hesiod's Works and Days, Pandora lifted the lid to release the jar's contents.
The action is simple but decisive: the evils had been contained, Pandora opened the vessel, and they flew out into the world. Hesiod does not describe her breaking the jar or smashing a seal. The image is one of removing or raising the cover, after which she closes it again.
Many paintings and modern stories turn the container into a chest with a hinged top, which encourages details such as locks, keys, or broken seals. Those additions are not the essential action in Hesiod's account. The standard narrative says that Pandora opened the jar and then replaced its lid, leaving Hope inside.