Editing green location after flight.

This would be restrictive to the settings on the watch or the course mapping. You would not be able to change the green location as a result. You can review the following support article for things to check for in the event there are inaccurate or incorrect distances in relation to the green.

-Resolving Inaccurate or Incorrect Distances

You can also make sure your golf course data on the watch is as accurate as possible by updating it with Garmin Express.