Hi @Anonymous,
I hope you're doing well. The easiest way is to use the INFO command and click on the line you wish to change the style for. While drawing lines look at the top toolbar near the right you'll see the line style combobox. The other way you can change the line style is to use the CHANGE command. This is probably the best way to do it if you are working with groups.
Best Regards,

Jorge Garcia
Product Support Specialist for Fusion 360 and EAGLE
Kudos are much appreciated if the information I have shared is helpful to you and/or others.
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