So I've performed this mod for about a year ago. Several guys asked me to publish this in english, so finally it's here: http://oleg.wl500g.info/wl700ge_flash.html

Russian mod thread is here: http://wl500g.info/showthread.php?t=7048

This mod is only needed if you to want flash "big" firmwares, which do no fit to 2MB, for example my own WL700g-... version.