how do I change the course stroke index on holes that are wrong on Garmin g80

Ensure that the course maps are up to date on your Approach G80 by connecting it to a home computer and installing updates through the Garmin Express program. Steps outlined on support page linked here: Update Golf Courses and Device Software on an Approach Golf Device

After updating the course maps, if you are feel any of the handicap or index information is incorrect, after the next few scorecards are recorded (as draws from the best rounds from the last 10 scorecards from courses) then please submit a report through the course report form linked here: https://www.garmin.com/forms/golfcourses/

Below are links to pages on the support center site for the Approach G80 showing how to change the index on the device, and how to implement handicap scoring manually:

• Approach G80 - Setting A Player Handicap
• Manually Entering Handicap on a Golf Compatible Product