For resetting a Mitsubishi Multi Communication System (MMCS), there isn't a single physical "helpful paper," but there are several highly useful digital guides and manuals
If the soft reset fails, you must perform a hard reset. This completely cuts power to the unit, forcing the capacitors to discharge and the RAM to wipe clean. The most effective way to do this without specialized tools is by removing the radio fuse. mitsubishi multi communication system reset
The system is frozen, unresponsive, or lagging. mitsubishi multi communication system reset