Fridge is leaking refrigerant, do I have to buy a new one?

Some units need to have the door removed to provide enough clearance to remove the entire frig. Depends on the size of the frig and the door size. Or you can remove the exchanger first, then remove the unit.

However, the exchanger can be replaced on the dinette table and easily fits through the door. I've removed mine to bring it out of the unit and it was an easy job.

Only disadvantage of not replacing just the exchanger is all of the other components such as electronic board, frig casing, etc is not upgraded.