magnet:?xt=urn:btih:790B6F4D044893DD1DABED7556788B44F04D5F68&dn=gargoyle_1.9.x-x86-generic-combined-ext4.img.gz&tr=udp%3a%2f%2ftracker.openbittorrent.com%3a80%2fannounce&tr=udp%3a%2f%2ftracker.opentrackr.org%3a1337%2fannounce
Download and unpack the .img file.
I use a Windows pc and the program USB Image Tool to restore the .img file to a flash drive.
Then simply plug the flash drive into the x86 router and power on

Connect to one port at a time to see if you get a 192.168.1.x IP assigned.
Your biggest issue might be the NIC driver. I tried many x86 routers and with pfsense I found that my NIC use Intel IGB.
A few pros and cons:
I don't know yet how to build the stable build or the experimental. Only the current on git.
The Connection | Basic page is odd. Like way too many elements are displayed. I had to click around to close all of them in order to make changes. First then was I able to save. Next time on that same page I had the same problem.
When I want a newer build I have to build it my self and transfer it to a new flash drive. If it doesn't work I can easily use the old flash drive.
Cannot add plugins (USB, webcam, AdBlock) - maybe they have to be build into the image.