Finding a specific physical manual for OEM motherboards like the can be difficult because Lenovo does not typically release "do-it-yourself" style manuals for these boards. They are proprietary boards manufactured for Lenovo (often by Intel or ECS) specifically for their desktop towers (typically the ThinkCentre M-Series, such as the M800, M900, or M910s).
If you lose the supervisor password, the manual instructs: Move JP1 to pins 2-3 for 10 seconds, then return to 1-2. This clears both user and admin passwords. Lenovo Is6xm Rev 1.0 Motherboard Manual
After installation, you need to configure the motherboard to ensure optimal performance. Here are some general steps to follow: Lenovo IS6XM Rev 1