The Manual Way.
take the manual, and each setting will be denoted by "(Default)" , go through and manually set each setting back to factory defaults.
Using the PC software.
Watchpower for all Models EXCEPT the Hybrid 2424, and LVX6048WP, and LVX6048
Solar Power ONLY for models shown above
software can be downloaded from MPPSOLAR.COM
there is a tab called "Factory Defaults" or similar click that