New used ThinkPad

I just purchased a Thinkpad G40. It was a rental return and was at a great price. However I needed to make some bios changes. When I tried to access the bios it would let me into the user area but the changes I needed required me to log into the bios as supervisor. Now someone in the past (this being a 6 month old computer) has created a Supervisor password in the bios. Does anyone know of a program that will read the cmos and display passwords. According to IBM the solution is to take the machine in and have the motherboard serviced (replaced). I think thqat is rather drastic. removing the cmos battery wont work. It does change it back to default settings but doesnt get rid of the password. And it causes a date/time error tht you need the pqassword to log in and correct. TIA