After I import an assembly from either a STEP or Parasolid file, I often don’t care about the assembly structure and I sometimes don’t want all the hardware that is in the file, I only want the main solid or sheet bodies. The method I use is to set the selection filter to Bodies, then select all the bodies from the graphics screen I want to keep then right click on the Outline and choose Move to New Component. I give that new component a meaningful name, then I open that new component and save it. Now I can save and close the original file that I opened as I don’t need anything in that. If I later find I missed a body I need, I can open the original file where my named component exists and make that the Active component. Then I can find the missing body, select it and on the keyboard, type Ctrl-X and Ctrl-V to cut the body from the original file and paste it into my named component file.