The deathstar(s) have a very large superlaser, torrents of anti-capital guns, and tin-foil space fighters. It is the size of a small moon.
The macross has a fold generator, bow-firing main particle cannon, torrents of weapons, a pin-point barrier generator (later omnidirectional barrier), and entire flights of capable transforming space fighters armed with Reaction weaponry.
The empire has Darth Vader, who can use the force to pick out main characters from the entire plot. He flies a unique Tie Advanced with two laser cannons, shields, and supposedly hyperdrive.
The UN Spacy has Hikaru Ichijo and Max Jenius, and if they're lucky they have Millia and Roy Focker. All of them are flying some version of VF-1 with a GU-11 Gunpod and likely FAST packs with a full load of missles and reaction warheads.
There would need to be a reconnisance mission by the SDF-1 to determine the weakness of the Deathstar (no way they're going head-to-head, or Misa would surmise), and they find the exhaust port. So the mission turns into dropping a reaction warhead down the exhaust port.
Darth Vader has trouble taking care of one measly farmboy from Tatooine flying an X-wing that cannot transform (yet has no problem with veterans). He'd have one heullova time confronting, say, Roy Focker. Skull squadron would eat him alive.
Then Hikaru saves the day by dropping a reaction warhead down the exhaust port and Minmei sings the theme song to starwars- confusing imperial leadership so they don't see this all comming.
In the case of the Death star II it's much simpler: Fold behind the thing and fire through the incomplete superstructure to annialate the core.