hi,
I’m trying create a pose as reference for a four armed character, and I’m hoping to add two more arms. my idea was to
1.open mannequin file
2.duplicating the mannequin subtool
3.deleting all other stuff in second mannequin other than arms
4.attaching it to the original mannequin
but, I’m struck at step 3, I wasn’t able to remove root mannequin, I was able to delete other via alt+click.even if I some how I figure it out, I’ve no clue how to achieve 4th step
It’s not possible to ‘cut and paste’ parts of a mannequin like that. You can add new zspheres to create new limbs. You would then insert meshes using the Adaptive Skin>Insert Connector Mesh but this can be a bit tricky. There’s some info here, lower down the page:
http://docs.pixologic.com/user-guide/3d-modeling/modeling-basics/creating-meshes/mannequins/
Anyhow, I added a couple of arms to one of the existing mannequins which perhaps will suit your purposes:
thank you so much for the help 
and
You would then insert meshes using the Adaptive Skin>Insert Connector Mesh but this can be a bit tricky
could you please shed some some light on the process ? I mean that’s how those mannequins got cylindrical shapes in between z spheres right?
All the information you need is at the link I gave you. See the section “Making your own Mannequin”.