Unfortunately, the option to manually remove offline devices on your account page is no longer available.
If you've already reached the 5 devices limit, and attempt to add a new device, Spotify will automatically remove any downloads from the one device that hasn't been used in the longest amount of time. Reinstalling the app will also remove any downloaded music from your device.
Keep in mind that if this is something you'd like to be able to do on your account page, you can also consider adding your +VOTE to this idea. The Community team is actively bringing your feedback to the internal teams at Spotify - check how here.
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