I seem to recall i could just click on the edit device and then delete but i don't seem to see a delete button anymore. I've attempted to remove the old integration and the device objects still exist. prefer to do it bulk but i'll have to do it one by one if needed.
for context i have alexa media player integration and i had to re-create it but now it has double the devices. but really the same goes for any other device on any integration.