Weapon Coils and Outfit Weaves are found throughout the game, generally when you kill a machine. Once you acquire one (it doesn't matter what it does), slot it into a weapon/outfit and this trophy will 'pop'. The first place you can easily acquire Mods over and over, including the Very Rare ones, is in the western portion of The Embrace (Southwest of Rost's). There are several Scrappers, kill them, collect items, save and reload at the Campfire a little East of the site and Reload. Happy Hunting. :)