High alkalinity

My parents have a pool that I'm looking into the chemical balance on and the first test I took shows a pretty high alkalinity level of 560ppm. It took 56 drops in my Pentair test kit which seemed like a lot. The tests came back with the following levels. Free chlorine 0.5-0.6, total chlorine 1.5, PH 7.8-8.0, alkalinity 560 ppm. The test kit says to address the alkalinity first but by my estimates and the calculators I've seen that will take about 24-30 gallons of acid which seems like a lot and that it would take a very long time to add that much as my mom was told the maximum acid that can be put in the pool at a time is 2 litres. The pool is a heated, indoor vinyl pool with a capacity of about 30,000 gallons. I'm not exactly sure on how the chlorine is added but I believe there is a dispense in the pump room that pucks are dropped in. I've read so many different opinions of alkalinity and how to put acid in the pool that I really don't know where to begin now. Some say pump on some say off, some say slug, some say mix and disperse around the edge of the pool. I'd really appreciate some guidance on where to start. Is addressing the alkalinity my top priority? If so, how do I apply the acid and how much should I start with? Pump on or off? Can acid damage the vinyl liner by sitting on it in the bottom of the pool? Any help would be very appreciated, thanks in advance!