This works on the 2000 and 3000 series generally.
*The easy way is to just hold the mode button for 10+ seconds.
The full/proper way is below:
1.) Either power on the unit and hold the "mode" button or hold the "mode" button until you see the below:
00:04:08: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvram
00:04:08: %EXPRESS_SETUP-6-CONFIG_IS_RESET: The configur........