Ok...I'll give you step by step as per the factory Helms. You may not like it...but it is the only way! (ask me how I know!)

1. drain coolant (I'm sure you've done this)
2. remove the heater control valve cable clip
3. remove heater hoses from heater core
4. remove heater core nut on fire wall in engine compartment

here comes the fun ones

5. remove dash
6. remove heater ducts from heater core
7. remove steering column bracket

...and finally,

8. remove the two nuts from the top of the heater core.

I've played the game and I HAD to do everything listed!