How to replace UBports with Android on Nexus 5.
I was able to locked/unlocked and load UBports on the Nexus 5 with the Magic-Device-Tool. However, it did not install Android [ Install Factory Image]. Nor did I find any relevant information in the UBports wiki.
Nevertheless, it was possible to re-install Android on Nexus 5 after consulting the following references that provided guidance:
Removing Ubuntu & Reinstalling Stock Android On Your Phone
Factory Images for Nexus and Pixel Devices
[How To] Reinstall Android After Trying Ubuntu Touch
Installing Ubuntu Touch on a Nexus 5