If you already have GIMP-Print then this printer requires no additional installation! Just plug it in and use the Ubuntu Add a Printer Wizard.
System >> Administration >> Printing >> New Printer
Follow the instructions and be sure to select the driver for the Epson Stylus Photo RX500.
I use XSane for scanning:
Applications >> Graphics >> XSane Image Scanner
If you don’t have GIMP-Print already, it is easy to install.
sudo apt-get install gimp-print
Now go back and follow the instructions at the beginning of this post and you will have a working Epson Stylus Photo RX500 Printer/Scanner!
