Seth and Aurel aren't sure, aside from just needing to absolutely massacre the Swarm with every bit of firepower that can be brought against it.
The Hsrik and Dar have a different sort of contribution, however. The Swarm itself is a massive collection of killer insects. Such an entity needs a guiding hand. And they know where that can be found! The heart of the Swarm- its ferocious Queen.
The Queen and her Swarm were, at one point, put into a sort of containment field by the Bollans of old, after their betrayal by the Garans and before they shunned technology. What triggered the return of the Swarm is, to the Hsrik's chagrin, the Garans helped the pirates pilfer some gear from the tomb-like structure that contained the Queen. Namely the high-powered generators that kept the energy fields in place.
The Garans and the Bollans need to rally their forces if an assault on the Queen is to be launched. Only the Jedi will be able to strike at the Queen herself- her armored shell is extremely hard, if the legends are true, so only your lightsabers will be able to cut her down.
Everyone else will hold off the Swarm while you do the deed.
While you are waiting for your armies to assemble for the fight, you have a little downtime. Do you want to do anything in particular before the fight?
Aurel reminds you that the crewmembers of the Dawntreader are still reluctant to join the fight. Trawley, the first mate, and Harvik, the bounty hunter, are with you but considering what they actually came here for. Their mission was to deliver supplies, not fight wars against monsters and pirates.
And none of this has been reported back to Captain Kart or the rest of the crew, who are laying low to avoid drawing the attention of the pirates above.