Apart from arm.002, all the parts of the arm are parented to the empty Object called "arms".
If you select "arms" and then SHIFT Select the parts that you want to 'set free', you can ALT+P > Clear Parent > Clear and Keep Transformation.
If you want a left/right separation, you'll need to Apply the Mirror Modifiers and in Edit Mode: P > Separate by Loose Parts.
Hooo. I missed that part. I had to select only one side before separating by loose part. That was the problem. thx
Is there a way to separate by loose part all the parts in one operation so it will be much faster?
That is the pose I wanted to make, just like the concept art, after separating the meshes.
I guess if you select multiple objects and enter edit mode at once in all of them and then do separate by loose parts, I'm guessing it works all at once, but I'd have to put that to the test.
Is there a way to separate by loose part all the parts in one operation so it will be much faster?
It's a bit tricky in this case; not really a one-click solution. The fastest way I can think of is: you could Select one piece and Delete the Subsurf Modifier:
Then Select the other parts and CTRL+L > Copy Modifiers:
Then (keep the selection!), Object > Convert > Mesh:
This will remove all Modifiers on the selected parts, meaning in this case the Mirror Modifiers.
Now (again, keep the selection!), you can add a Subdivision Surface Modifier on the Active part, set it to the wanted Level (I'd say, Level 2) and then: CTRL+L > Copy Modifiers.
Go into Edit Mode on all parts (just keep the selection) and P > separate by Loose Parts.
The (in my opinion not so big) downside, is that you originally had some parts with a Subsurf Level of 3 and others at Level 2.
It's so long. It's because I have to learn. Sometimes I stop following the course and I just try all kind of things to understand better the mechanic of the program.