Just like PIVOT syntax, UNPIVOT syntax is hard to remember.
When I can, I prefer to pivot and unpivot in the application, but here’s a function I use sometimes when I want don’t want to scroll horizontally in SSMS.
Click through for the function. This is an area where I wish there was built-in * logic for PIVOT and UNPIVOT. Or at least a “Select all columns but the following” as that would make things easier.