Plug the device into a computer.
Select the Windows key + E.
Select This PC (Windows 10 only).
Select the Garmin device drive.
Open the GARMIN folder.
Select the Activities folder.
Press Delete on the keyboard.
Confirm you want to delete the Activity folder.
Select your product to confirm this information applies to you
How Do I Delete All Information From My Device?
The following devices require a two step process to erase all user data and settings:
Edge 20
Edge 25
Forerunner 10
Forerunner 15
Forerunner 30
Forerunner 35
Before a master reset is performed you will want to connect the device to a Windows or Mac computer and delete the activity folder from the Garmin drive. These steps will have to be performed on a computer since a master reset does not delete previously saved activities from the device's internal memory.
Delete the Activity Folder
NOTE: Do not delete unknown files outside of the Activity folder; deleting necessary files from the device can cause adverse performance issues.
Perform a Master Reset:
Power off the device.
Press and hold the two right keys.
While holding the two right keys, press and release the power key to turn the device on.
After the first beep, release the upper right key.
After the second beep, release the bottom right key.
Your device will now be erased of all data and personal settings.