Transmission cooler replacement instructions needed?

Hello!

I'm seeking advice about replacing the transmission cooler (radiator) situated in front of the A/C radiator.

There is a small leak caused by a collision with a deer.

I would like to know what types of couplings are there, how to disconnect them, the implication of disconnecting them, how to refill, compensate, the possible lost fluid back in the transmission.

I would also need to check the transmission fluid level. I don't think that the car is equipped with a stick for checking the fluid level.