My plan to install a larger transmission cooler

Here's my plan, before I dive in I wanted to post it here. Maybe someone will poke holes in the idea before I make a mistake.

I was thinking that I would be able to clamp off the rubber lines going to the existing cooler, and swap it for a larger cooler.

I could fill that larger cooler with transmission fluid before installing it.

I figured I could make this swap without having to taking the truck in for a coolant check/fill.