I'm doing catchup from the beginning of the year entering transactions month by month and then reconciling. I did January and reconciled. I went to do February and realized I did not change the default reconciliation period for January. As I did that in July, the reconciliation period set for January was recorded as 7/1 - 7/30. 

I need instructions on how to undo this.

I've searched the community. Everything I find is 7 - 11 years old and the interface does not seem to work in that manner anymore.

I have figured out how to "undo" the previous reconciliation but, that does not seem to allow me to change the reconciliation dates.

I only have the one reconciliation for this account in there at this point.