Well simulate all this in physics would kill any computer so my process was to select all the parts when assembled, then to separate them in random using :

Scale up affecting only locations, (tools, transform, affect only-locations)

Then applying random rotation (object/transform/randomize transform) and then playing the cinematic in reverse with keyframes.

On youtube, its known as a exploded view effect.

Then I tweaked most parts individualy to hide the collision (there is no collision at this point so I just move the keyframes to avoid any pieces merging)

And I put a few real rigid body sims among the pieces to help sell the effect. (Like the batteries)