Minimize boot time on headless ubuntu

I am trying to remove as much processes as possible to minimize the boot time on a beaglebone running ubuntu minimal. So i want to remove udev-fallback-graphics and all plymouth processes. I tried 'sysv-rc-conf' and 'rcconf' and 'update-rc.d -f' and nothing worked. By removing those processes i can gain about 4-5 seconds which is very important for the project i have. The dmesg gave me this:

[    7.855712] ADDRCONF(NETDEV_UP): eth0: link is not ready
[   10.704010] init: udev-fallback-graphics main process (443) terminated with status 1
[   10.853881] PHY: 0:00 - Link is Up - 100/Full
[   10.854125] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[   11.418457] init: plymouth main process (174) killed by ABRT signal
[   11.446380] init: plymouth-splash main process (470) terminated with status 2
[   13.843292] init: plymouth-stop pre-start process (686) terminated with status 1

Solution 1:

https://askubuntu.com/questions/19320/whats-the-recommended-way-to-enable-disable-services

upstart services aren't affected by any sysvinit config tool. Apparently, to disable SERVICE, you need to create a file /etc/init/SERVICE.override containing the word "manual".