Get a test of the water , hardness and iron...
That is an older meter... but the valve is a 5600 metered unit... good long lasting..
Maybe a rebuild kit or trade with some one that has a rebuilt valve body with control on top with the meter..
While the media tank is out of the brine tank, get what is called a brine well and replace that thin thing that they are calling a brine well on the inside of the brine tank.
Put a brine float assembly in it.. much better water flow in to and out of the brine tank..
You should also replace the drain line, looks to be a kink in
So when this all starts to go down after you have all the items on the list ... the three gate valves.. the two that are in line with the softener will get closed and the middle one opened and you will still have water.. unscrew the two screws one on either side of the meter, brass yoke assembly.. once those are lose you will be able to pull the whole unit away from the pipe and yoke. The valve unhooked from the brine line and drain line and unpluged will unscrew off the top of the media tank, the tan tank in the middle of the salt..

With me so far?

Step at a time....