This is the most common fix for "full" tanks. Turn off the water supply.
The most manual method but effective for small amounts. Wet/Dry Vac: The fastest way to suck out excess brine. 40278 water softener full
Take a broom handle and gently push down on the salt. If the top layer is hard but there is hollow space or water underneath, you have a bridge. Break up the salt carefully to allow it to mix with the water again. This is the most common fix for "full" tanks