It's still work in progress. Finding the installers wasn't hard, but my parents are old and the options are complex, so it took them a while to select the vendor and heat pump.

Right now they are awaiting government approval for their application (it's been very popular and they are swamped, and even had to increase the budget allocation). They also had to do preliminaries like upgrade their electrical connection and add 3-phase wiring in the home, as well as build a concrete platform outside the house to stand the heat pump on.

The heat pump itself should be a drop-in replacement that uses the existing hot water radiators (which means it can't be used as A/C, unfortunately).