Change boot screen in Ubuntu

Steps give below for how to change boot screen in Ubuntu
open terminal and run this command then you will be able to edit
sudo gedit /etc/default/grub
after you run the command it will ask you for you password. enter
note the picture you want to use needs to be in your home folder
here is a copy of mine
GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=-1
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”
GRUB_CMDLINE_LINUX=”"
GRUB_BACKGROUND=”/home/user/happ.jpeg”
note the last line and you must use the quotes
save changes and while in the terminal type sudo update-grub .
that should do it