There is no way to delete or edit post on thread that have been moved to the archive board.
It is not possible to delete or edit a thread in any board, although in the archival board it includes replies to a thread as well.
There is no restrictions to editing a thread or reply in the archival board.
The thread in question is locked, so the OP won't be able to do anything with it.
On the other hand, we're dealing with a sockpuppeting troll, so who knows what their problem is.
Yes suchmoon are right. If I see the wrting
then I don't have to bother asking this question sir.