Before you touch a wrench, know this: you're just interrupting the main water line. The softener needs to treat all the water coming into your house—except the outdoor spigots (you don’t need soft water for your petunias, I promise). The goal is simple: cut a pipe, insert the machine, and connect the drain. That’s it (okay, and a bypass valve, but we’ll get there).
You’ll need a few tools: a pipe cutter, a couple of wrenches, some Teflon tape, and maybe a propane torch if you’re using copper. If that sounds scary, don’t panic—you can use SharkBite fittings instead. They’re the duct tape of the plumbing world: too easy, slightly expensive, and deeply satisfying to click together.