Where can I find the free plug-in to import .coe files in AutoCAD?
The plug-in is available on the Leica website, but it's necessary to have an account and password in order to download it. There is also a manual/user guide that can help you use the plug-in while AutoCAD is opened.
Access the page using the following link: http://hds.leica-geosystems.com/en/Support-Downloads-Cyclone-COE-Downloads_29456.htm
Note: After clicking download on an item, the login form will be displayed, or you can register for an account.