Trying to create a macro to change drawing units to inches 3 decimal places, can someone help me out?

I am really new at trying to write macros, but am not great at using it with the solidworks API yet. So i am hoping to get someone to write a macro for me. We change from fraction (IN) to decimal (.123) in our drawings when we go from customer to production. I am hoping to get  a macro that will make this a single click action. Also, if possible add notes in the macro to allow me to learn what is happening. I am working in solidworks 2015.  Trying to kill two birds with one stone here.  thank you in advance for the help. 

SolidworksApi macros