Changing root password in UNIX

1) Do u have Linux Installations CD's
If yes, do this
1) Boot the server with Linux CD-1
2) After booting, at the boot prompt, write linux
rescue
3) It will go through a series of steps
SAY Yes/Continue to them. U can say no to network
interface...'
At last step, tt will give u the location of ur
installed OS image
(Most probably it will be /mnt/sysimage/source)
4) Finally, it will give u the bash shell
5) bash > cd /mnt/sysimage/soource
6) cd /etc
7) vi passwd
8) There will be an entry like (root:x:0:1.......)
9) Remove 'x' from the above entry. (Do it cautiously)
10) Save the changes to passwd file
11) Reboot the system
12) U can now login as root without any password.
13) Change the password for root usinf passwd command

Now since ur root, just su to oracle owner
1) su - oracle
2) connect / as sysdba (This will connect u as sys)
3) Change the sys password