You would be best off getting a plug in 24VAC transformer to run the thermostat off of (one wire goes to Rc and one goes to C) and connecting the red and white from your current wiring to Rh and W1.
Otherwise you would need to run new wires from your boiler to your thermostats, and the connections don’t appear to be labeled at all on the boiler, so it would require quite a bit of trial and error.
See this thread for more info on using an external adapter.