Sorry not to have replied sooner but I'm playing Lost Company at the moment and took my eye off the general thread.
When the antennae appear to regenerate Zimmerman in the Scorpion, you can shoot at them and destroy them. Once the three antennae are destroyed you can finish it off (though you won't have seen the end of Zimmerman
)
For a video walkthrough, check out the vid in "Tips and FAQs" on Blood's and my
NVN Guide