|My guide gives example IP addresses. You're not expected to change yours to match.|
If your existing router's LAN IP is 192.168.1.254 then make the second router's LAN IP 192.168.1.2 or any other IP address that is outside the DHCP scope defined on your first router.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.