[Trisquel-users] Changing An Application Icon In Main Menu

[davidpgil]

Hello All! I'm using Gnome with Trisquel and I would like to add an  
application link to my main menu software listing. I know how to add a  
software to the list and link it, but how to I add my own custom icon graphic  
to it? Which format does it accept? I tried a PMNG image at 48x48 and it  
doesn't seem to work. Any help with this?

I prefer a gui-based solution over command-line, but I am open :)
Many thanks!

- David