Quick Steps: Highlight reference. Right-click. > Edit Reference > Edit where needed > File > Close Reference > Yes to Save.
Step-by-Step:
Highlight the reference you want to edit, and go into editing mode by selecting References > Edit Reference from the top menu bar. Alternatively, double-click the reference.
Select the field that requires editing. Make the necessary changes.
Save your changes by pressing Cmd + S on your keyboard or clicking the red exit button and selecting save when prompted.