It's basically plugging the yellow cable into the green port on the back of the ATV which gives you a black and white pic, then use a HDMI to DVI cable attached to a DVI to VGA adaptor to force a change to color, then a step or two with remote buttons to give you the proper resolution for a non-HD monitor.
(Apparantly the adaptor does something to the unit to trick it into giving you a color picture with a press or two of the remote. Once you have color, you just remove that cable/adaptor. $15-20 for both, but a necessary expense for a color picture.)
All very simple...although I have never tried it.