1. Go to Settings on your device  
  2. Go to the Calendars option
  3. Click ‘Accounts’
  4. Click ‘Subscribed Calendars’
  5. Locate the ECAL calendar you are subscribed to (Most likely the publisher name)
  6. Click this Calendar name
  7. Tap Delete Account to confirm

Don’t see the “Accounts” option? Click here.