I would also be grateful if you would delete all 5 of my devices.
Why on earth we are not able to do this ourselves is a mystery. I'm a grown up after all !!
Thank you for posting to the Community.
We are very sorry for the delay in response.
To remove a device, you will need to access your account and head to 'Device Management' from there you will see a list of registered devices.
You will also see an option for Replace/Remove.