Hey Ian.
Yes, it is that easy, but make sure that the system has been evacuated prior to opening it (sounds like that was the case).
Installation of the condensor is pretty routine. It's theoretically a good idea to replace the r/d every time the system is opened, but in my world of hack A/C repairs, that often gets overlooked.
Make sure that, when the system is refilled, you have them vacuum it for at least 15 min. This will help to verify the integrity of the repair.
Best, whit