Help w/ converting old hater water radiator system thermostat to smart thermostat

[Jeff Davis]

Hey all - 

Wondering if anyone has experience switching out an old Honeywell thermostat that is used for a hot water heater system to a smart thermostat (we bought the Amazon smart thermostat). - see attached photos

It's for our new airbnb listing. We are in the process of rehabbing an old 2-story multifamily building and the thermostat for the entire building is on the 1st floor which is where the Aribnb will be. We would like to be able to control this remotely thus we need to switch the thermostat. 

Have been unsuccessfully in finding someone that has experience doing this at a reasonable price as this is our first rehab. 

Any help would be greatly appreciated!