After signing up for a (free) account on tunnelbroker.net and creating a (free) tunnel with my ipv4 address as the endpoint I was able to easily configure my AirPort Extreme. View your tunnel, then click on “Example Configurations” and then “Apple Airport.”
In TCP/IP prefs for my MacBooks Network/AirPort Preferences I have “Configure IPv6” set to “Automatically” Then BOOM “ping6 en.blog.wordpress.com” works just fine.
IPv6 without needing my ISPs support and it didn’t cost me an extra dime. Happy World IPv6 Day