Hello @Utterly Disillusioned,
You can uninstall Bitdefender from that device following the steps described here and also remove the device from Bitdefender Central. The device must be removed from Central in order to free up the slot. To do this, follow the instructions below:
Afterwards, using your Windows 10 device, follow the steps described in this article, just like a normal installation:
Let us know if the information was helpful.
Best regards.