How do I change the Ubuntu loading screen? [duplicate]

You can do this using the update-alternatives command. You'll need to do this twice -- once to select the graphical boot splash, and once to select the fall-back text boot splash.

Open a console window and run:

sudo update-alternatives --config default.plymouth

Enter the selection number for the line containing ubuntu-logo.plymouth.

Next, run:

sudo update-alternatives --config text.plymouth

Enter the selection number for the line containing ubuntu-text.plymouth.

Finally, update your initramfs. Run:

sudo update-initramfs -u

Reboot your PC, and you should see the Ubuntu boot splash return.