How To Edit Datagrid Column Template?

[Scott Rossi]

Continuing work on a datagrid and can't figure out how to edit the column
template of a specific column...

I'm looking at the RunRev lesson on editing the column template.  Apparently
the column whose template I want to edit already has a custom behavior
associated with it, so I can't click the "Add custom column behavior" button
(disabled).  Switching to the Basic Inspector pane and clicking the Row
Template button, the result doesn't look anything like the screenshots:
there are no buttons to edit, and I can't tell if I'm editing the row
template of the column, or the row template of the whole datagrid.

Anywhere else I can look to get some more info on editing column templates?

Thanks & Regards,

Scott Rossi
Creative Director
Tactile Media, UX Design