How do I fill the radiator with coolant w/o a cap?
 

hello,
I've got a 2004 motor home with a Ford F-53 chassis and a Triton V-10.

I'd like to change out the coolant myself with out taking it to a garage. My problem is, when I drain out the old coolant how do I add new coolant without a radiator cap? I have a pressurized recovery tank but it's only got a 3/8 hose going to the radiator; hardly big enough to fill it up.

Also, how would I flush out the system?

Thanks for any help