Rax20 How to change/set lan IP address ???

For what specifically? 

For a device? 

For the router.? 

Maybe telling us what you're trying to do in detail can help more than vague questions. 

https://kb.netgear.com/24088/How-do-I-change-the-LAN-TCP-IP-settings-on-my-Nighthawk-router

As plemans says, tells us what you are trying to achieve. Changing the LAN address is rarely necessary.

Manuals are always a good place to start.

Visit the support pages:

Support | NETGEAR

Feed in your model number and check the documentation for your hardware.

Look for the model number on the label on the device.

You may have done that already. I can't tell from your message.

I mention it because Netgear gave up on supplying paper manuals and CD versions some years ago and people sometimes miss the downloads.