Below is a complete list for the locations of all minikits in Chapter 02: A Loki Entrance.
Part A MInikits
Minikit #01: Drop off to the lower level at the beginning, and look around for a red box that Hulk and can open. This piece will be inside.
Minikit #02: Check along the right side of the area for a gold gyroscope, and have Ultron mess with the thing within it to claim this minikit.
Minikit #03: Head to the right end of the catwalk and hit the target you see there to get this one.
Minikit #04: Head to the left end of the catwalk where you'll find a terminal for Thor to charge up.
Minikit #05: For this minikit, you'll want to descend along the staircase not far from Loki's first position where you follow the path to a busted machine. Both Ultron and/or Tony Stark can fix it.
Part B MInikits
Minikit #06: Check the rear left section of the garage for a Shield switch that you can activate. Scarlet Witch can then use the red key to open the safe for this piece.
Minikit #07: Check the rear right section of the garage for a vent that Vision can pass through.
Minikit #08: Enter the room to the left and have someone who can use lasers to slice through the golden wall inside.
Minikit #09: Once you've activated the sprinklers in the garage, send a Hydra agent, such as Baron Strucker to operate the S.H.I.E.L.D. terminal to claim this minikit.
Part C MInikits
Minikit #10: This minikit should be visible during the early sections of the tunnel car chase sequence. Switch control over to Maria so you can snag this collectible when you see it.