I understand how to get to the PDF customization what I am having a pro

I understand how to get to the PDF customization what I am having a problem with is that I don't see where to change the PDF from two columns to one column.

If your PDF report is in two columns, delete your current PDF template and create a new one then choose side by side layout.

Here's a screencast for better guidance.
Give it a try and let us know if you need more help.