Divide a multibody part into different parts

Insert>Features>Save Bodies ...
If you need more explanation just let me know.

This might be helpful: http://gupta9665.wordpress.com/2010/11/10/assembly-from-part-no-mates-required/

Hi andreas. multibody parts should not replace the use of assemblies. a general rule to follow is that one part (multibody or not) should represent one part number in a "Bill of Materials".
a folder named "Solid Bodies" appears in the FeatureManager design tree when there are solid bodies in a single part document. The number of solid bodies in the part document is displayed in parentheses next to the "Solid Bodies" folder .

try this it may be help you

Select commands to apply to all bodies within a folder.

List features that belong to each body.

Thank you for your answer fssane!!
I am modeling a tft monitor and I finished the front part, and in order to design the back part, i need the back surface of the front part (i don't know if you understand what i say). I don't like using assemblies for such things because the mate refferences go crazy when you try to move one part. It changes the sketches you have used as reference.

yes Andreas i get what you mean. Couse of mate refferences u cant make changings on the any of part. firstly what part you want to make changes select part right click and then "show mates". u need to inactive or delete mate refferences.
and if refferences in the sketch of the body u have to re-mate and delete old mate refferences.

or the other way convert the assbly file step. and re-open it in other folder. all the sketch mates will be deleted solid works ask you to recognize the each part say it ok.

Awesome help people this solved a real headache for me.