I'm presuming the Empire knows both where and who they are.

Easiest solution seems to be to not be there. Even with the Empire on the hunt for them, flying away should be a feasible option, and once they get to hyperspace they should have some breathing room.

Second option would be hiding out on the planet. Sure, it's a toxic hellhole, but it's really, really, really hard to find a small number of people on a huge planet -- look at the stormtroopers failing to find the droids on Tattoine. Hiding a ship makes it harder, but see if the players have any great ideas.

Third option, hiding amongst the masses on the station, though if the Empire is just going to blow the station up, maybe not the best idea.

Fourth option, have them infiltrate a group of Imperial soldiers, incapacitate them, impersonate them, and escape on some Imperial ship.

Fifth option, provide an out. Flashing back to Empire Strikes Back here, have them captured, but have an NPC of some influence break them out with a chance of escape.