First welcome to the Forum.
Hope you enjoy your new 5er and 2500 CTD Dodge.
I do not know much about the Pullright Easyglide hitch although a lot of people use them.
I have a 15K Reese manual slider hitch in my 2500CTD Mega Cab Dodge with a short box.
As far as using the hitch I would think you will need to line the king pin up with the receiver on the hitch. I leave the jaws closed and unlock when I back-up the king ping opens the jaws and will close when hitched correctly. My DW stands to the side and ensures that the pin box is low enough for the pin box to ride up on the receiver and have the king pin engage the jaws on the hitch. I would think the Pullright would be the same.
Here is a site that might help you understand and provide information on the Cummins in your Dodge and the Dodge truck. It does cost to join but I believe it is will worth the $35 a year. I been a member for three years.
http://www.turbodieselregister.com/
Jim