I looked at this when I put seat covers on my wife's 02.  I ended up
leaving the armrest in the up position and fitting the cover over it.
The cover had plenty of elastic to fit over and it is barely noticable
unless you know to look for it.   Check here for some instructions...
http://www.hmaservice.com/webtech/default.asp

If my memory serves me there is a zipper that runs the lenght of the
armrest starting from the end closest to the pivot point.  The end of
the zipper is really tucked in so you might need something to grab it
with.  Once the cover is off you can probably figure out what keeps it
in place.   Again I went for the easy route and didn't get beyond the
zipper.  that sounded strange :)

BTW...  Don't put seatcovers on 03 + accents.  They have the side
airbags in the seat that will not be able to deploy if covered with by
a seat cover.