Hello,
Find the queen and put her downstairs with the excluder (well positioned or a new one), let the bees from the super emerge before even considering harvest (min 24 days because they are likely drones). You might consider a upper entrance to let the drones get out so they don’t get trapped by the excluder.
There have been a number of messages about how to clean the cocoons out of the super but I’m not sure there is a consensus that this has to be done straight away.