Just in case someone running Win XP is interested, this is how I accomplish   
   changing my IPv4 address for my IPv6 tunnel.   
      
      Needless to say, you have to change all the various IP addresses, but once   
   you've done that, all you have to change is the IPv4 address (the   
   localaddress) in this batch file:   
      
      
   netsh int ipv6 install   
   netsh int ipv6 6to4 set state disabled   
   netsh int ipv6 set teredo disable   
   netsh int ipv6 isatap set state state=disabled   
   netsh int ipv6 delete interface he.net   
   netsh int ipv6 add v6v4tunnel interface=he.net localaddress=81.230.165.57   
   remoteaddress=216.66.80.90   
   netsh int ipv6 add address he.net 2001:470:27:302::2   
   netsh int ipv6 add route 2001:470:27:302::2/64 he.net   
   netsh int ipv6 add route 0::/0 he.net 2001:470:27:302::1 publish=yes   
      
      Take it or leave it -- it seems to work for me...  8-)   
      
      
   ..   
      
   --- Mozilla/5.0 (Windows; U; Windows NT 5.1; sv-SE; rv:1.9.1.16) Gecko/20101125   
    * Origin: news://eljaco.se (2:203/2)