I've owned a few. They look a little different, but they work pretty much the same way. These notes probably apply to any brand softener especially the ones that are self-contained and with an electronic interface.

When salt pellets are added, it's a requirement that the salt level be set manually using the Select button, then the up- or down arrow to select a setting between 0 and 10. Afterward, the unit thinks it knows how much salt is left. When the level reaches 2, the display begins to flash so that passers-by notice and make a mental note to buy more salt.

Pressing the Select button multiple times gets you to the time-of-day-set, recharge-time, water-hardness, etc. menus. I set the time of day and recharge times when needed, but I've never mucked with water hardness—too geeky to do that in my book.

To initiate regeneration, either after recharging the salt pellets or really any time you want, just press the button on the left of the Select button (see above). To initiate immediate regeneration, press and hold this button until you hear it kick off. This action is common to all Sears models I've owned. (On the units at both my homes, this is the button at the lower left.)

When you've left the unit un-by-passed to run without telling it about the salt level, the resin beads will be "worn out" and it will take a number of regeneration cycles to get things working the way they should. This usually happens as a result of procrastinating the purchase of salt pellets.

Even though the controls are older (for the one at the left, above), more sophisticated and don't look like [the one on the right, above], they do work this way.

The resin beads are little charged beads made of a plastic inside the tall, heavy cylinder that accompanied your water softener. The charge on these beads is opposite the charge on the minerals in your water (magnesium, calcium, etc.) and they attract those metals and hold on to them as the water goes by. This is what makes your water soft.

Over time, these beads get gunked up with metal deposits and need to be cleaned or refreshed. This is how to do that.

Purchase brand Iron Out rust stain remover. On Amazon, this is a $15 bottle of powder that you put into half a gallon (2 quarts) of cold water in a bucket. Measure out 1 cup of the powder into the water, then stir it in until homogeneous.

Next, remove the cap to the brine well. It's probably

1. in the salt barrel,
2. round in shape about 4" in diameter,
3. grey in color and
4. caps off a tall, black 4" diameter tube most of which you can't see because it runs down into the salt pellets in the barrel.

It doesn't matter if you spill any on the salt pellets in the barrel, but ensure that most of it goes down that black tube.

Replace the brine well cap just as you found it before.

Now trigger a regeneration cycle using the control buttons on your water softener. On my Sears-brand softener, this is done by pressing the ON/OFF/HOLD button and holding it until it kicks off (which I can hear). Other systems have a Recharge button. If in doubt, read the manual.

This was a good video (if it's still there):
Water Softener Cleaning.