If you are the group owner or moderator, you can remove any post in
your group. You'll need to log in with the same account you use to
manage the group and view the post in question. Clicking the "show
options" link next to the date will display a blue "Remove" link to the
far right. Click this link, select "Yes, remove it now," then click the
"Confirm" button.
Also to do more testing on remove post, add a test record to this tree
and see if you can remove it. Or better yet see if you can remove this
post.