Ok so I’ve managed to find an article on the net about how to change
the default applications menu in Ubuntu, this will enable you to
change it to whatever you like (instead of the default distrubution
icon) Itâs dead easy, but everyone else tries to make it sound so
complicated. So hereâs the dead easy way to do it.
First, youâll need to download your image. I used this one from
Wikipedia as itâs already in the required .svg format, otherwise
youâll have to convert to this format using The GIMP. Donât just
rename the file!
Save the file to your Desktop with the filename start-here.svg and
fire up the terminal.
Now youâll need to find out what icon set youâre using. In Ubuntu this
is simply a case of going to System / Preferences / Appearance,
clicking the Customize button, and selecting the Icons tab. Iâm using
the Tango icon theme, but youâll need to substitute Tango with the
name of your icon theme in the following commands.
Okay, so in the Terminal we need to run this:
cd Desktop
sudo cp /usr/share/icons/Tango/scalable/places/start-here.svg start-here-old.svg
sudo cp start-here.svg /usr/share/icons/Tango/scalable/places/
killall gnome-panel
The first command changes to your desktop, the second creates a copy
of your old icon on the desktop (for backup purposes), the third line
copies the new icon over the top of the existing one, and the final
command restarts your gnome panel. Whew!
Hope this is helpful to others looking to achive this! 
