Do I have to emty out the radiator to change the radiator fan switch or can I do it with fluid still in there, but with the motor cold?

 

yes its just screwz that hold ur fan on and disconter the conneter

 

Not the fan, I want to take out the coolant temperature switch, its the sensor that is on the rad....hose when it goes into the head of the motor, can I remove it with out emptying out the coolant

 

Put a rag under it and start to remove. you'll figure it out from the way the next 30 seconds come out to be.

 

In my experience the best way to do it is to remove just like 500ml - 1L of coolent.
Just pull the plug from below the radiator drain a little bit then remove the temp sensor. U could try a rag but it doesn't work that well and u end up with coolent all over the tranny, block and engine bay and its hard to clean it, ie tight space to clean.