Required Character: Darth Maul
Death Star Plan 1 (Darth Maul): In this first area. There is a forceable platform you can put together in the upper corner. Put it together and jump up.
Death Star Plan 2: Head to where the start of the previous level was. It's sitting there.
Death Star Plan 3: Sitting at the top of the stairs after taking down the force field. Head back up the stairs and you'll find the plan.
Death Star Plan 4: In the secret room. Again. These guys are very creative with their plan placements.
Death Star Plan 5: A nice one, in the third area of this part. It's sitting right in the middle.