Some folks want to take the water softener with them when they move, and others just want to be rid of it. So how do you remove it?
If you plan on removing the water softener, you have to connect the loop back so that the house will still get water. As water enters the house’s plumbing, it is diverted into the softener and back out (except for the kitchen sink). When a softener is removed, there will be a void where the piping used to be. You just need to reconnect these pipes.
After you turn the water off to the house, disconnect the piping at the softener. Typically you will find that there are some male adapters on each end of the loop, and the lines leading to the softener are just threaded onto those. Use a wrench and unscrew the supply lines where they connect to the male adapters. You will get a little water that comes out.
To span the void left by removing the softener, you can use copper, copper flex, or braided. The flex is nice because you can just screw the ends on and be done.
You will have to disconnect the drain line from the stub-out in the wall. When you do, I would cap that line.