You can add the 'pull-right' class to the icons:
<ul class="nav nav-tabs nav-stacked bs-docs-sidenav span8">
<li><a href="#Variabler"><b>Variabler</b><i class="icon-chevron-right pull-right"></i></a></li>
<li><a href="#Datatyper"><b>Datatyper</b><i class="icon-chevron-right pull-right"></i></a></li>
<li><a href="#Funktioner"><b>Metoder</b><i class="icon-chevron-right pull-right"></i></a></li>
...
</ul>