How to replace air conditioner thermostat?

How hard is it to replace home a/c thermostat with a programmable one. And how much do they cost?How to replace air conditioner thermostat?it's easy, you just have to disconnect and reconnect some wires in the back , they are color coded and come with instructions, you can get a good one anywhere from $20 to $60 for a dual unit versionHow to replace air conditioner thermostat?most thermos are 4 wire. red[ power] white [heat] yellow [cool] green [fan] mark the wires as you remove them [tape] reinstall on to the new stat and mount read the programing instructions and apply.common sense helps a lot.a good one costs about 50.00 to 100.00 dollars.probably 40%of my service calls are program able thermost problems .they are a lot of trouble if there are more than 2 people living in the house .i have the old reliable round honeywell thermostat.a setback stat seems like a good idea but the reality is you or someone is home more often then you think.you end up over riding your program.