The ink pads in the bottom tray will be full. It is very fiddly, and very messy, but you can take them out and wash them out.
See also:
http://www.howtomendit.com/answers.php?id=54655
and
http://www.fixyourownprinter.com/
and
http://www.ssclg.com/epsons.shtml
and
http://www.ianwillis.co.uk/c42/
The last site relates to another Epson model but I found it invaluable when taking the 830 to bits. There are 1 small and 4 large pads that need all the ink rinsing out.
Good luck.
ChicksFan
July 2010