Steps to make a bootable USB to install LinuxCNC.

I am trying to  install the Trixie/Debian/linux cnc  image that RodW recommends. Can't seem to find the right steps. I have the mesa cards, 
HP core I5 computer with 16 gigs of ram and 1 tb hard drive.  I have been using computers for a long time but I can't seem to make any progress
doing this install. Suggestions?  Any help will be much appreciated. I have had the Plug and Go kit for a few years and would like to get it working for the control of an engraving machine I am building.  Thanks Jeff