I have opened a gear from the 'Tool Box' and it allowed me to change the number of teeth, etc. which was fine, now, when I tried this same thing for its mating gear (2nd gear), I am unable to find the pull down that allowed those changes to be made. In addition the options that seem available are related to it being an assembly or part of an assembly.

Was I just lucky the 1st time? How can I achieve the results that allow me to make the gear a component? Reason being I need to make some changes to the blank.