sorry, meant to put it in.
The method/process is called swaging. You can actually buy the swaging parts at Home Depot. It takes a special tool, a swaging press or swaging pliers (they are big, like an 18-24" pair of bolt cutters). Depending on the strength needed, you can smash them with a hammer/pliers. This amazon link has a pic of one type of tool (cheaper than the pliers I have, and much more reasonable size), the crimping sleeve (also called a ferrule), and a wire thimble (look at the "frequently bought together" pic). You could also probably take it to your local welding/fabricating/hydraulic shop to do it for a reasonable fee.