Transferring part mobility from one subassembly to a higher one

Say I have a subassembly that has a shaft in it.  The shaft is constrained via mates in all degrees of freedom except for rotation.

I then take that subassembly and drop it into a higher-level assembly.

How do I rotate the shaft from the higher-level assembly?

I just tried doing this and the shaft rotation is apparently locked in the higher-level assembly.

Thanks for any help.

SolidworksAssemblies