Editing Lenovo ThinkPad P1 (section)

=== Installing with GRUB ===
It should automatically boot to the flash drive if you have it plugged in. You should see a GRUB screen. 

Edit the first option by pressing <code>e</code>. Before <code>---</code> in <code>quiet splash ---</code> (you may have to press up and right arrow to get to it because it doesn't show line breaks. The "\" at the end of a line means the line continues onto the next "line" of the screen), insert <code>modprobe.blacklist=nouveau</code> so the installer doesn't freeze.

(This is before the casperfs.whatever on the last line)

Press Ctrl+X to boot into Ubuntu installer.

If something weird happens, it may be the case that your flash drive is corrupted, so burn the image to your flash drive again in Rufus and try again.

If Ubuntu prompts to check your filesystem when booting, don't let it check your filesystem. Just in case. It won't do much if it checks the filesystem but it may corrupt Windows partitions by mistake.

Now go into the installer.

'''Turn off Secure Boot in the Ubuntu installer. You don't need to set a password for that. You also don't have to install third-party software.'''

You can set the bootloader partition to the Windows bootloader partition. Now, where you shrunk your disk and now have free space on it, click on that partition, and click Change... > Mountpoint > / and click OK.

You can click OK on the next screen when it asks you to confirm.

You can connect to the internet to get updates when installing.