'98 Blazer Coolant Drain

I tried to drain the coolant using the plastic pet cock on the right side of the radiator only about 3 quarts came out. How do I drain the remaining 8 quarts?

Pull block drain plugs and lower rad hose.
Or you can flush threw a heater hose and then add pure coolant.

Thanks for the reply,

1. I'm planning to flush from the heater hose which connects to the intake manifold and leave the lower radiator hose connected so the flush will drain out of the block into the radiator and out the drain petcock.

2. If the block is now full of fresh flush water, adding pure coolant to fill the radiator will that produce a 50% mixture?

3. And the big question should I refill with new DexCool or something like Peak Global?

I always run it untill it quits pumping out the heater hose.
I always like to get 2 gal all together of pure coolant in engine/rad/coolant tank .
Pulling lower hose lose helps drain some more out of it.
I would stay with dexcool.
But that is your choice.
Another solution is the universal antifreeze.
But mark the system so if someone adds too it they get the right stuff back in it.

I would stick with the Dexcool also. It can have an adverse reaction with other coolants.