What is best procedure? 2007. Had to disconnect resevoir and upper hose to get to alternator for replacement.

 

If you remove the radiator cap, that allows atmospheric pressure to push coolant down thru the lower radiator hose and push air up to the highest point of the engine/cooling system, upper hose. Just loosen the upper hose enough to allow any trapped air to exit. This is only done when engine is cold,which you already know..
If there is no point on the engine to do this,you might need to run the engine some (few minutes) to circulate the air to the highest point.

 

I don't know the design of the cooling system in 2007, but my 2013 Edge V6 has a hose leading from the thermostat housing to the top of the coolant reservoir. That's supposed to enable self-purging. On some car engines, there is a manual bleed valve on top of the thermostat housing. For the unfortunate, there is no bleed valve, requiring the old fashioned, laborious methods for purging air.