That is because you will need an Astromech Droid and a Bounty Hunter not available in story mode.
If you started the game from Episode IV, you could use R2-D2 and Boba Fett, but you will unlock the latter when you complete the Hibernation Station mission in Episode V.
It seems like a lot of work, but that is not a problem for you because you are a completionist, and as always, you will have step-by-step instructions on how to complete every This Is Some Rescue Challenge.
How To Complete Lego Star Wars: The Skywalker Saga This Is Some Rescue Challenge #1
You will have to discover the hidden room within the Death Star for the first Challenge.
The hidden room’s location is at the beginning of the mission after meeting the Imperial Officer, who is allergic to wookiees.
Chase him down, killing everything that stands in your way, and he will lead you to a locked door with golden bars on it like in the next screenshot.
After you clear the enemy troops and destroy the turret mounted on the ceiling, switch to a Bounty Hunter. Then shoot at the golden bars on the door and open the secret room to complete the Special Edition This Is Some Rescue Challenge.
How To Complete Lego Star Wars Skywalker Saga This Is Some Rescue Challenge #2
The second Challenge is to find a more uncivilized way to help Luke and Leia.
So get to the part of the mission where you see Luke and Leia behind a locked door.
Then, take care of the stormtrooper that is having a little lunch break right there, at the controls.
Now go to the last window on the left and shoot at the red button above the locked door, like in the following image.
Doing so will open the door, and you will complete the Bullseye This Is Some Rescue Challenge.
How To Complete Lego Star Wars This Is Some Rescue Challenge #3
The last Challenge will have you discover an alternate method across the gap to escape the stormtroopers.
To do that, you will first have to get through the locked door leading to the gap, in Luke’s and Leia’s part of the mission.
There are two ways of opening the door.
The fastest way is to switch to a Bounty Hunter and shoot the door’s golden bars to get it open.
Or you can go upstairs and find the Imperial Officer holding the keycard.
Anyway, after you get past the door, you have to go to the Astromech droid console and switch to R2-D2 to use it.
Doing so will extend the bridge across the following gap and complete the For Luck Challenge in the mission This Is Some Rescue.
Be careful not to get too close to the door near the console because you will start a cutscene putting you on the other side of the door, which you can’t get back from, and you will have to restart the mission.
And those are all three Lego Star Wars Skywalker Saga This Is Some Rescue Challenges in the game developed by TT Games.