If you just need an ipv6 address for LEAF router, you don't have to do anything and can skip step 4. But in most cases you like to have an authenticated tunnel (esp. with dynamic ipv4 adddress) or obtain a /48 prefix delegation for your LAN and probably to subnet a few more ipv6 networks.

To get an authenticated tunnel or a /48 prefix delegation, go to www.freenet6.net/register.shtml and create an account. Accounts are mandatory on Freenet6 if you want an authenticated tunnel or a /48 IPv6 prefix delegation. The authenticated tunnel provides one single and permanent IPv6 address to a node in spite of Ipv4 address changes. The /48 IPv6 prefix delegation is how you get a bunch of addresses for those hosts inside your LAN.

Please note that the "username" on the registration page is misleading - it will be the name of your machine/router.

After registration you will receive an email with your "username" and password form freenet6.net.