I have new 6.2's. I have drained all the water (3 drain plugs and a vent cap removed and now reinstalled). The owners manual states:

IMPORTANT: Mercury MerCruiser requires that propylene glycol antifreeze, mixed to manufacturers instructions, be used in the seawater section of the cooling system for freezing temperatures or extended storage. Make sure that the propylene glycol antifreeze contains a rust inhibitor and is recommended for use in marine engines.

But it does not say how to fill the engine. Attached is a picture of the thermostat housing. There is a pipe plug on top. Would removing that plug and filling from there do the trick? I want to make sure I completely fill the block and manifolds.

The owners manual also recommends to mix a batch of gasoline, 2-cycle oil and fuel stabilizer in a remote fuel tank then run it through the engine. How do I connect this tank to the engine? Do I have to install a T-fitting or 3-way valve between the boat gas tank and fuel pump?

Thanks for any help.