How do you create or edit a detail symbol to be used in a detailing symbol style?
For modification of the cells, here are the steps that you can do. There are quite a few steps and it does involve creating a new cell library because the delivered cells that we have are in a read-only ustation.dgnlib file.
There is also information in the help under Composing Drawings > Drawing Composition Workflow > Placing Detailing Symbols. Check the headings "General Procedure - Providing custom cells and creating placeholder fields" and "To create a detailing symbol style using custom cells".
How Can I create custom detailing symbols