[Zope] how to migrate from TextIndexNG to TextIndexNG2

[Marc Lindahl]

I'm importing (trying to) a plone site whose catalog has TextIndexNG 
indices into a new zope which has TextIndexNG2, and getting all kinds 
of errors.... is there a *real* way to migrate from TextIndexNG to 
TextIndexNG2?  Can I have both installed at the same time?

(errors are of the kind:
2003-12-19T16:13:59 ERROR(200) Catalog catalogObject was passed bad 
index object <TextIndexNG instance at ee17540>.
)