[DeTomaso] Cooling system reverse flush?

[Matt]

I'm pulling my radiator to fix a small leak and wanted to do a reverse flush of the complete system,including the heater core. I searched the archives and my manual and came up empty on advice or tips. One thought was do I need to pull the thermostat?  How about additives to assist in loosening any bad stuff before I do the flush? 
Where are the best locations for an entry point and exit?
I appreciate any help or advice as always folks.

Thank you,
Matt Wells
3584