To do this:

1. Press and hold the Reset button on the bottom of the device.

Observe the light on top of the node. It will flash bright red, then dim out in three pulses, followed by one last bright red flash. This process takes about 10-20 seconds.

2. The router will reboot and the light will turn solid blue, which means that the node is ready to be set up again.

Find out more:

How to set up a Linksys Mesh router after a reset