I previously looked into this thread: https://openerp.my.openerp.com/nl_NL/forum/Help-1/question/How-can-the-system-administrator-re-open-a-fiscal-year-51929

But I can't find the answer to my concern.

I closed the periods I previously made because I want to delete everything I have done in Accounting as part of my trial and error.

Then I started to clear the supplier invoices I have made. But then I was not able to do. The error message says, "You can not add/modify entries in a closed period ... " How can I re-open this closed period?

I went to the Periods section under Periods but it is empty. I went to Fiscal Years section and I was able to see there the other two periods I previously made and deleted. The status is closed and grayed-out. I want to re-open it so that I can delete the invoices.

I noticed on the thread above that there is a "Re-Open Period" button. Where can I find that?

Or is there any other way for me to clear out all the data under Accounting in OpenERP?