If the system was purchased directly from the company, go back to the salesperson and ask them why the documentation wasn't included.
If the system was purchased from a reseller, go back to them and ask why they didn't include the documentation that ships with it.
If the system is truly brand new and you are the first person to own it, then you have a warranty...
A warranty gives you credentials that let you log a SR with technical support. Do that, and ask TechSupport for help.
You might also choose to get all the PDF documents related to that box, and make yourself an archived library for it:
If you have access to the system console the solution is easy:
Just press any key to enter the Grub boot menu.
Then add an uppercase letter S to the end of the kernel line to start into single user mode.
Then simply type passwd to change the root password to whatever you want.
And just for the record, it also works in OEL 4.8.
Configuring kernel parameters:
Setting hostname to vm041.example.com
Checking root filesystem
Remounting root filesystem in read-write mode:
Enabling swap space:
Changing password for user root.
New UNIX password:
sh-3.00# uname -r