- Go to the Kindle Management Site (for me, that was at https://www.amazon.com/gp/digital/fiona/manage)
- Delete Sleight of Mind #1: Crashing the Party from the Kindle library (use the actions... button)
- Delete Sleight of Mind #1: Crashing the Party from my device
- Wait a little while (15 minutes for me)
- Go and "re-purchase" the latest version of the story - today that's free, so your purchase price is nothing
That's all it took for me. If you have another method, I'd like to hear about it.