Lars spends a few minutes stretching his arms, shoulders and fingers, trying to warm them up a little.
He gets up and tries to shift the crane so that its arm is positioned closer to the skylight. If the process turns out to be extremely noisy, he stops. He also takes a moment to untie his grapple, and he ties the rope securely to the roof, so that ha can make a quick getaway and not lose the grapple.
When that is done, he takes 20 to pick the lock holding the skylight closed. Assuming he succeeds, he looks down and watches for movement below. He then carefully lifts the window open. He listens carefully, praying that the beasts below don't start howling when they feel the wind and humid air from above.