2011 Ford Taurus Add coolant to radiator

How do you add coolant to a pressurized system. There is no way to add it to the radiator as there is not a cap system on the radiator so I cannot add it directly to it. I've added about 5 quarts to the coolant and to the hose that flows to the radiator. After doing those 5 quarts how do I add the other 6 so I'm at 11 that is required for the entire system?

I cannot get any to flow into the engine. Here is the prob. Clean slate from beginning. I added three quarts to degas reservoir and that includes whatever ran down hose into radiator which has no place to add it manually. So it has 3 quarts in it. Let cat run for 15 mins with cap off and level didn't change but heater was blowing heat which I get but after 2 mins the fans kicked on to cool the cat due to know antifreeze flowing through system. Cannot add any more cause the antifreeze never left the degas reservoir. Is there a way to bleed the system so it goes into engine and I can add more or does it newsboys I go to a shop and have a machine that forces it trough the cooling system. If you could tell me the exact steps for the whole process when flush is complete and want to add new antifreeze to the cat if appreciate it. It's the 3.5 duratec and I have not seen a bleeder valve or any guide to doing this would be great.

Will doing that pull antifreeze into the engine so I can add more and get all 11 quarts in. I won't do that if it causes damage to my engine. I'm skeptical because I can't find it anywhere else on the Internet. Is that something they would do at a ford garage and have you done that to that specific engine?