how to unlock sap* and ddic in bi server

hi experts,

we installed long back bi server in windows 2003 on vm were.but we forgot the password.we are using db as oracle.

i tryed by changing the parameter login/no_automatic_login_sapstar=0 and restarted the instance.but even though i am unable to login that.can any one guide me how to unlock them if any alternate procedure is available. we dont know even the other users also in this server.it's completely locked is there any possibility to unlock at least 001 client.

thanks&regards

kishore