You already have it. In NX 11, many of the utilities got moved to the "NXBIN" folder (they are no longer found in the UGII folder).
Note that you can do "make displayed part" and continue working.
There is no MUST convert in this, mixed unit assemblies is reality for many users and there is nothing wrong with that. the ONLY thing you cannot do is "make work part" when the part and the assembly have different units.
see this GTAC article:
Production: NX10.0.3.5 MP16/TC11.2
I'd rather be e-steamed than e-diseaseled