Adventure Level 3: Rathtar Hunting - Loading Area
A significant amount of your time in the last section of the level will involve shooting things and being shot at, so watch your back as you collect the last of the minikits.
Minikit #1 - Free Play Mode
Head over to the left and use the force on the flower over here.
This will get you your first minikit.
Minikit #2 - Free Play Mode
To the upper left of the flower you'll spot some gold Lego rocks.
Destroy them and a minikit will fall on top of you.
For the next minikit you need to destroy five of the glowing blue flowers either during or after the shootout. You can see the location of three in the screenshot above.
The other two are to the right.
To the left is a crate with a grapple plug.
Pull it open and you'll get another minikit to the bonce.