If you submit a post prematurely, and you do not think you can edit and fix it well within the allotted 5 minutes:
1.
Edit the post with the 'Advanced' editor.
2.
Select all of the contents in the editor window. ( Ctrl-A )
3.
Copy or
Cut the contents into the 'clipboard'. ( Ctrl-C or Ctrl-X )
4.
Delete the post.
5.
Start new post.
6.
Paste the contents into the editor window. ( Ctrl-V )
7.
Continue editing.