I see that I could do it this way, but there is a limitation. Here is what I would do if I was to delete the last segment:
1) Export GL_Account to Excel/csv
2) Remove the last segment in the Excel sheet.
2) Use Data File Display and Maintenance: GL:AccountStructure.M4T Delete the last record.
3) Do a VI import job into GL_Account
However, this is why the above won't work: The VI data dictionary for GL_Account only has the field Account. Field AccountKey is not available!!!
Does anyone have a solution that they could share???