Tesla to upgrade V3 Superchargers to 300kW

[dan_b]

https://www.teslarati.com/tesla-superch ... elon-musk/

How are they doing this I wonder? Does this apply only to new installs, or are existing ones able to be upgraded by software?
Does that mean existing cars like the Model 3 will be able to absorb the extra 50kW or will that only be for new battery chemistry models down the line?