Weeping Trans cooler lines. How to add fluid after replacing?

So I recently had a transmission flush at the dealership last week. I removed my grill to install some LED pods and saw a lot of dirt build up and oil residue on my Trans cooler lines.

My co-worker and boss said my lines are shot and need replacing coining the term "weeping." Showing me the lines were very spongy and are loosing atf through their pores.

I'm just curious how to add atf back into the system from what I loose out of the lines and cooler themselves when I do the line replacement?

Can I just fill the cooler and lines as much as I can and quickly attach the line hoping that the miniscule amount of fluid missing isn't going to effect anything?

 

Hi Bishop, The transmission is filled on the side of the trans, you will need a little hand pump they sell at harbor freight or home depot.
you take the plug from the bottom of the pan and start the truck. Let it warm up and add oil to the fill plug until it seeps out of the plug on the bottom. there is a sticky on it for trans flush. Its very easy but you need the pump good luck