Unpivot column pairs in Power Query for Excel & Power BI

Often you have column pairs or (or threes or multiples of more) that you want to convert from columns into rows for analysis purposes, I go through the process here using Power Query, including what to do to deal with multi-row headers and the extra step if you have duplicate names in certain places. This is a process I find myself using very often.
I mention these other tutorials in my video:
Power Query multi row headers: • Fix multi row headers ...
Power Query Pivot Column: • Pivot Column in Power ...
You can download the example files here: www.xlconsulting-asia.com/you...
00:00 Introduction
01:06 Unpivot with no duplicates
05:42 Duplicates and multi row headers
09:39 Column triples and blanks