If you're an Android or Google account user, this is really simple but must be done from the web browser at https://calendar.google.com
On the left side of the screen you should see "Add a Friend's Calendar" or "Add a Coworker's Calendar". In the text box, enter the email address email@example.com and hit enter. There should be a new entry for the calendar under Other Calendars. Feel free to change it to a different color so it stands out from the rest of your calendar entries.
If you're using the built in Calendar app on iPhone or other Calendar applications, here is an iCal link you may use - https://calendar.google.com/calendar/ical/calendar%40troop671bsa.org/public/basic.ics
Send an email to Mr. Short if you run into problems.