The simplest way is just dump the iso into a usb stick
by dd (in linux) or any other similar tools,
supposed you built the honeycomb-x86 or ics-x86 which
support the hybrid iso format.
If you'd like up update it manually, just copy the files
in $OUT: kernel, initrd.img, ramdisk.img, install.img, system.{img,sfs}.
--
Chih-Wei
Android-x86 project
http://www.android-x86.org
Patrick