For Outlook:
Click the button ICAL and open the ICS file using Outlook. It will add the above calendar to your list of Outlook calendars.

For iCal:
Click the button. ICAL It should automatically open the file using iCal and ask you what you want to do with the new events, choose 'New Calendar' and click 'Ok'.

For Google Calendar:
Click the button above in the bottom right hand corner of the calendar on this page. It will take you to your Google Calendar account where you will now see the Cathedral of Praise calendar added to your list of 'Other Calendars' on the left side of the page