You may or may not be stymied here depending on the level of the password. I suppose my first question is why don't you don't get the password off the person who set it?
Those error codes usually mean the the CMOS backup battery need replacing. As to how to, I suggest that If you go to www.lenovo.com (Lenovo own all of IBM's PC assets now) you can download a maintenance manual. Step through the diagnostics in the manual.
t
November 2007