Remove authorized devices/ UNauthorize?

I have a couple of devices that I want to remove from my Adobe ID but in neither case is it possible to do that on the device. If I don't remove these two devices then I will exceed my maximum limit and it will also be possible for someone else to use my Adobe ID and put material onto even more devices and lock up my ability to read the things I have paid for.

One item I need to unauthorize is a stolen Sony PRS505 reader. Obviously I can't do anything that requires me to press any buttons on that item as I do not have it. I will be replacing it and will need to authorize a new device in its place, but first need to remove the authorization belonging to the Sony - how do I do that?

The second authorization that needs to be removed is a computer whose PSU has blown. I've taken the hard drive out and mounted it onto my other PC, but I'm not able to boot it as a virtual machine or anything it's just mounted as a drive. How can I remove the authorization from that machine so I can let someone else have it? It's the only piece of private data still on that machine (it was a home theatre PC, it had next to nothing on it besides simple documents, videos, etc.) and i can't work out how to get it off as I don't have an option for uninstall or anything like that while it's mounted as a data drive.

How do I unauthorize these devices so that I can authorise two new ones in their place? (deliberate alternation of UK and US spelling so it comes up in both searches!)