To get there from the airport (Zürich Flughafen), we need to go through the main train station (Zürich HB), which is a 10 minute ride from the Airport. From there, we walk to find the #7 tram, which leaves from Zürich, Bahnhofstrasse/HB. Then it's a 6 minute ride to the Ottikerstrasse street.
Yes. Walk out of the front entrace to the station, you'll see a tram stop straight ahead. That's not the one you want! Instead, carry on going straight and cross the bridge. You'll see another tram station called "Central". That has the number 7.
Mike, do you know - could we buy the 24 hour day passes (Green button :-/) ahead of time, and then just validate them as our former ticket expires?
Sorry, I don't think so. The ticketing system in Zurich is rather primitive, because all the locals just buy yearly passes. You'll find most people just walk on and off, without buying tickets - that's why. Make sure you have coins!