If using an AN, power it off, then open it and put a jumper on pin S16, behind the power LED. If using an ANH, power it off and put a jumper on pin DB7.
Power ON the AN. The unit completes the boot cycle in diagnostic mode. At the Diag prompt, type wb c0000 12345.
Power OFF the AN, remove the jumper and re-boot. When Login prompt appears, log in as Manager and there will be no prompt for a password. Set new password as desired