drivers - Ubuntu 16.04: how to boot into nomodeset from GRUB2 tty? Laptop with only NVIDIA M1000M

I installed Ubuntu 16.04 on a laptop solely equipped with NVIDIA M1000M graphics card. During installation I was able to edit the boot options from the GRUB menu (the one with try without installing, install, install as OEM) and add nomodeset to the boot command. If I didn't do this I would get a purple screen rather than the installation process.

Once Ubuntu 16.04 was installed, however, I can't figure out how to add nomodeset or boot into a terminal-only mode so I can install the necessary drivers. These are the things I tried:

1. hold shift while booting to load GRUB menu, but it never loads.




2. hold Ctrl+Alt+F[1-6] to go to terminal but didn't work.





3. hold Esc while booting gets me to the GRUB terminal. how can I boot into a nomodeset or terminal only mode from here to install the right drivers?

For context (not sure if these are relevant): BIOS has UEFI, 2HDs with RAID0.

Thanks!