English is the standard language of this forum, use it.
Basically what dustin said. Enough forktube to clamp on with a double clamp is all you need really.
stick a long ass metal pipe/screw driver in between the fork legs and have it snugly fit against the deck/headtube and spin it hard, thats what i do with mad rusty forks, normally works
Search please...
http://www.scooterresource.com/forum/search.php?searchid=193551
See how searching helps? just look through those threads, you should figure it out.