As long as the contents of the hard drive are not encrypted, you can physically remove the drive and use a USB adapter like this one to retrieve your personal files.
You can try removing the CMOS battery for several minutes, with all other power sources disconnected. This will reset all BIOS settings to their default settings, and may remove the passwords as well. However, getting to the CMOS battery requires fully disassembling the computer and removing the system board to gain access, something that maybe overwhelming for inexperienced users. (Page 13 of the service manual - PDF).
