Ok, check one more time that the radiator valve is closed and the engine block plug is installed and tight. Remove the hose from the radiator valve if you haven't already. Dump any old antifreeze that is in the drain pan into the 5 gallon bucket and put the lid on the bucket. Place the bucket in a safe area away from kids and pets.
NOTE: Using a mixture of greater that 60% glycol based antifreeze with 40% water can actually start to raise the freezeing point of the coolant so I would suggest never using more than a 60% antifreeze to 40% water mix.
Place a funnel in the degas bottle and add premixed 50/50 antifreeze until it reaches the cold fill marks on the degas bottle. If you have pure 100% antifreeze then mix one part anti-freeze with one part distilled water and then add the mixture until it reaches the cold fill marks on the degas bottle.
I used Amsoil antifreeze that is good for 7 years or 150,000 miles.