Settle Promissory note / unpost voucher

Hi all!

I’m now using AX2009.
As I posted a “Settle promissory note journal” without tick a journal at “Function > Settlement”
Is there any way to fix it? As i cannot entry into “Settlement” when journal is posted.

If not, can I unpost the voucher so that I am able to click into “Settlement”?

Big thanks!