I had the same experience. Epson website doesn't tell you an important step at the very beginning of the process. Before you open the scanner unit cover, you need to start by selecting Setup from the touch screen. Then select Ink Levels. Just below the graphic picture of your ink levels you will see two options, OK and Cartridge(s) Replacement. Select Cartridge(s) Replacement. Your printer will go into cartridge change mode. The touch screen will tell you to open the scanner unit cover. When you open the scanner unit cover, the ink cartridge assembly will have moved out into the middle of the printer, away from the right edge of the printer where you were prevented from opening the cartridge cover. Follow instructions from there at:
http://www.epson.com/cgi-bin/Store/support/supDetail.jsp?infoType=FAQ&oid=232592&foid=254104