Make sure you have a free electrical outlet and a computer near where you want the second router to be located. Plug it in and turn it on. For the purposes of this wikiHow, we will refer to the second router as "Router 2". Use an Ethernet cable to connect to the LAN port on Router 2. Then connect to the Ethernet port on a computer. This opens the admin login screen for Router 2. With most router's, the IP address is 192.168.0.1, 192.168.1.1, or 10.0.0.1. Use the default username and password to log in to the admin user interface for Router 2, just as you did with Router 1. Check the user's manual or manufacturer's website to find the default username and password.  With most routers, "admin" is both the username and password. Since DHCP is enabled on Router 1, it should be disabled on Router 2 to prevent IP conflicts. Locate the DHCP settings in the admin user interface and switch the DHCP server to “Off.” As of now, there’s a good possibility that Routers 1 and 2 have the same default IP address. To prevent IP conflicts, Router 2 needs to have a different IP address than Router 1.  Find the area in the routers admin user interface called “LAN” or “Local Network.” There should be a box that contains the current IP address. Type a new IP address in place of the existing one. The new IP address on Router 2 must be on the same subnet as Router 1. This means the first three sets of numbers in the IP address should be the same as Router 1. Change the number after the fourth period in the IP address to something different from Router 1.It also can’t be an IP currently assigned to another device. They should be identical to Router 1.  You should find these settings under a menu called “Wireless”, “Wi-Fi setup”, or something similar If you’re unsure of Router 1’s SSID and passkey, it should be printed on the device. Router 2 is not a wireless router, skip this step.

Summary:
Plug the second router in and turn it on. Connect a computer to the Router 2. Type Router 2's IP address in the address bar of a web browser. Log in using Router 2's username and password. Disable DHCP on Router 2. Assign a new IP address to Router 2. Configure Router 2's Wi-Fi name and passkey.