Instructions
Begin the Jedi Destiny level in Episode VI. Approach the Emperor with Luke and Vader, and start the fight.
Work the Emperor's health down by approximately five hearts. When he stuns your lead character with Force Lightning, immediately switch to your backup and continue attacking. Palpatine will retreat after he takes enough damage. Take out the Imperial Guards, who rush you immediately afterward. They are very susceptible to Darth's Force Choke.
Approach the pile of LEGOs that are next to the partially built fan. Mix the LEGOs with the fan and combine them with the Force to get it working properly.
Jump on top of the fan and ride the air flow up to the balcony above. When the Emperor electrifies the ground in front of you, make your way toward him by stepping on the darkened tiles, which keep you safe from electrocution.
Continue the battle with Palpatine; whittle his health down until he retreats again. Defeat the next wave of guards, chase him down and do some more damage. Palpatine eventually levitates up to higher ground.
Put the elevator together and have your characters levitate up through the shaft, one at a time. Continue attacking the Emperor and chase him down when he runs. When he drops back down, follow him and take away his last three hearts to bring the battle to a close.