I don't have pictures but I just did it.  My thermostat was original.  I didn't think it was cycling on and off correctly and this past weekend I was chatting with someone who recommended to go digital and described how easy it was (thanks Phil)

It was only 2 wires.  I put it back in the same spot.  I have heard of others relocating it due to it being too close to the furnace or being in an odd spot.  Mine was in the dinette away from the furnace.  I did not see any good place to relocate it to with out a lot of trouble so I just put it back in the same spot.  It cost $19 at home depot.  It is programable but I don't think I will be using that feature.