Login with with PuTTY SSH to the host with your usual username and password.
Go to the location of the HP tools
cd /opt/hp/tools
Create a new file
vi pwreset.xml
And paste this text into it (press i to insert text) and change the value=”password” into the password you want for the Administrator user.
<RIBCL VERSION="2.0"> <LOGIN USER_LOGIN="Administrator" PASSWORD="unknown"> <USER_INFO MODE="write"> <MOD_USER USER_LOGIN="Administrator"> <PASSWORD value="password"/> </MOD_USER> </USER_INFO> </LOGIN> </RIBCL>
Press ESC, type :wq and press enter. Then type this command
/opt/hp/tools/hponcfg -f pwreset.xml
You should get an output telling you the script has succeeded.
You should now be able to login into the ILO with the Administrator and the chosen password.
Source:
https://www.vcloudnine.de/reset-the-hp-ilo-administrator-password-with-hponcfg-on-esxi/