How do I Open Read-only Assemblies with all assemblies and parts read only?

Just want to open an upper assembly in Open Read-only and have other assemblies/parts read only.

I know there is this option but am constantly checking/unchecking or have to get write access to my parts.

On a side note....Bravo on speedpack. 

EDITED BY MODERATOR: Moved to the Assemblies space. Please post to the appropriate space when one exists.

SolidworksAssemblies