Buy a repair manual at NAPA, or AutoZone, or Wal*Mart.
how long does it take to install a heater core in a 2000 dodge neon
most of the time it the heater control unit on the motor not the heater core had same problem
follow the instructions here http://myfordfocus.com/how-to/oilchange.htm
Read the instructions that came with the aftermarket alarm and follow them.
Why don't you ask a mechanic?
Buy a kit at Wal-Mart or auto parts comes with instructions
where is the heater motor located at
You go by the instructions on the kit. You will have to cut a heater hose in order to install it. I assume you have a cleaner that you run in it before you flush the system. Open the drain under the lower radiator hose and turn on the water until it runs clear.
Go to NAPA and buy a repair manual for your specific car.
Check your fuses.
Go to AutoZone.com "Do It Yourself" tab for on line instructions.
http://www.qaparts.com/Recent/description8/Parts/Heater_Core/ here is a link for instructions hope it helps you