Script

[Anonymous]

Is it possiableto change already attach external references from "Attach" to "overlay" by a script?

I do not see that option!

Now I have deattach and attach agin chosing "overlay"!

[pendean]

You do know you can change that in the XREF command palette through a pulldown after you select he XREF(s), right?
-XREF command (the commandline version) can also do it for you if you use * when asked to select the XREF(s).

Try it and see: detaching and reattaching is an ancient irrelevant method.

[Anonymous]

The issue is to change from attach to overlay by script.

I can not see the option you mentioned.

[RobDraw]

[pendean]

No script, you need more, ask in the LISP forum for a customized solution https://forums.autodesk.com/t5/autocad-customization/ct-p/AutoCADTopic1