CVS Changing Head Tag

[alain delafosse]

Hello
I have a cvs reposity with a working branch "dev" and the trunk...
I want to forget the trunk and the branch dev becoming the main trunk
of my repository.
I read the manuel and saw something about forcing the use of a
specific tag in a workspace but nothing about this kind of transition.
I guess it would be something like an export of the old cvs repository
with the tag "dev" and an import to a new one; but how to keep the
releases of the branch dev.

Thanks
alain