It is very easy to create a SixXS tunnel. First you have to register on the SixXS website. After having done so, you will get some credits. Depending on the number of credits you have, you can apply for tunnels, further subnets routed to your tunnel, DNS server entries and so on.
You can obtain new credits by keeping your tunnel active for some time. Every two weeks you will be given five credits. So all you need to work with SixXS is patience.
The first step after registration is to apply for a tunnel. SixXS won’t manage tunnels by itself but delegates this task to one PoP. You should choose the nearest one (network wise) for you tunnel and give a short explanation about how you want to use it. After some time you will get an email that everything is configured.