Hope this helps.
1. Connect to one of your routers.
2. Go to your router address usually 192.168.1.1 or check your manuals.
3. Look for Network or LAN settings and open the page.
4. Look for like routers IP, Gateway or gateway IP address. If you can't find it look for the SUBNET without the mask just SUBNET.
5. Once you found it change the number of the third block eg."192.168.X.1" change the X value from 1-255.
6. next look for subnet mask make sure it's 255.255.255.0
7. Save changes and let your router to restart.
8. Repeat the process with the other router.
Once done do this next.
1. Go to control panel open network and sharing center.
2. click change adapter settings.
3. Right click the eternet adapter icon and choose properties.
4. Look for Internet Protocol version 4 (TCP/IPv4) double click on it.
5. In general tab click advance.
6. Look for the IP settings tab then uncheck automatic metric and set the interface metric to 1 then save changes.
7. Repeat the process with the other router.