How to extract classification schema from existing classified raster

[JadedEarth]

I have ArcGIS Pro v3.2 on Windows 10 Enterprise.

How do I extract an ecs file from an existing classified raster (i.e., Cropland Data Layer)?  I was able to export the Colormap file but can't find an easy way to get the .ecs file.  I tried "Merge Classes" tool but the "New" class column doesn't have a dropdown list that the documentation describes here.  I need to merge some of the classes in the Cropland Data Layer since there are too many redundant classes.

Appreciate your help.

[JordanCampbellUAF]

I have the same question. I have a classification (A) I want to use on higher resolution imagery (classification B). I want to use the schema from classification A for Classification B but get an error in the Classification wizard when I try to use the raster layer (A) to create a schema for B