After opening your team's profile, click on the "Schedule" tab.
Click on the "Stats" button for the contest you would like to edit.
When logged in as a team staff member you will see an "Actions" menu in the right sidebar.
Select the "Edit Statistics" option.
Select the "Open Stat Editor" option.
Select a player in the sidebar.
Not all stat keys will be visible (they're separated into categories). If this applies to your sport you can toggle the category above the player select list.
When finished, click the blue "Save Stats" button in the top right corner.
The text of the button will loop through each of your athletes and give you a confirmation when everything is good to go.
If you need to change statistics that were already submitted, go ahead and make the appropriate changes as if you were entering statistcs for the first time.
Clicking the "Save Stats" button again will remove the previous data and replace it with the corrections.