No heat, heater core is good,blower moter works

The complete removal is shown in this youtube video.
http://www.youtube.com/watch?v=vLdMYx6fhic

So you're getting heat but no blower to circulate the heat, right? It's also possible the fuze is blown to the blower motor, the switch that adjusts the speed of the motor could be damaged, or its resistors that limit voltage, to control speed could be "open" (burned up). I would check many of those before replacing the fan..

The heat is controlled by a valve that allows water to circulate through the heater core. If the fan is blowing cold air, check the valve, or blow water back and forth through the heater core to clean it out.

are you installing the correct thermostat the right in the head or block
3 thermostats indicate incorrect fitment method
heater hoses run either way as the water is pushed through the heater core by the pump

flapper door inside duct work not opening and closing properly. check my tips section for heat diagrams

check water pump working and no leaks..might be vacuum line not opening the flapper door or heater core, or heater control valve

Sounds like either a plugged heater core or a baffle inside the heat box is stuck

Over heat is caused by poor circulation of coolant. This problem can be: 1- The thermostat is not opening ( bad) causing coolant stagnant. 2- Water pump is bad, not circulate coolant. 3- Radiator is clogging up. It is full but water can not going through small clogging up tubes inside to have heat dissipated through the fines.
Since you also have no heat then I think the bad coolant causing the heater core clogged up also, unless the heater valve has a problem not allowing cooling flowing through the bypass hose to the heater core. Correct all 3 things above then you should be OK. Good luck.

the valve that allows the hot water into the heater core is not opening. most likely electronic issue. also check all vacuum and electric lines.

check valve at and before fire wall penetration should be in line with heater hose 

its not a fuse if the blower motor works , you have a clogged or bad thermastat, bad water pump or your radiator heater core is clogged