Access Kinderpedia from your computer / laptop using a WEB browser (Chrome, Mozilla, Safari, etc.).
Step 1: Go to "Activities" and click on the activity in the calendar.
Step 2: Click on "Edit activity details".
Step 3: Next to "Assigned teacher", click on "Edit".
Step 4: In the popup window click on the school / kindergarden name.
Step 5: Click on "Save" in order to save the changes. Now other teachers have acces to that activity.