Well crap.
I just tried to delete my post - because, according to Conservative, its against the rules and I dont want to get banned again.
But, the board won't let me delete. It wouldn't delete a duplicate post earlier.
I give up.
If your edit button is still visible, sure you can.
Click on the edit button and in the lower part of it, there is the delete option. I think you have to check a box, then the delete button of that window is no longer greyed out and you can delete.
Gonna post this and make sure, then I'll edit this to tell you more if needed.
ETA: Yeah, hit the edit button, then hit the delete button in that window. That brings up an additional section - the delete section - and change the checked box from do not delete to delete. Then the 'delete this post' button is no longer greyed out. Hit that, and your post is deleted.
You don't necessarily have to put a reason for deletion, either. Only if you want.