Required Character: Jar Jar or Darth Maul
Death Star Plan 1 (Anyone who can Jump): As you aren't using a jumping character at this point in Story. You'll need one to grab the plan on the platform above the panel for R4.
Death Star Plan 2: From here, use R4's hover ability to glide over the the pillars, a plan is sitting on top of one of them.
Death Star Plan 3: At the upper corner on the right side. Under a couple of canisters.
Death Star Plan 4 (Jar Jar): Before dropping down to fight Grievous. Jump up to the higher platform for a Plan.
Death Star Plan 5 (Jar Jar): Don't drop down yet, as you'll see a hole in the wall. Head inside to find the last plan.
Revealed Code: L, L, L, Right, Left, R, R, R