The ECM swap process itself is not very hard at all, if its your first time I would plan for 1-2 hours. My first time it took me 2 hours really taking my time, the second time I knocked it out in 30 minutes. My ECU came from CP so if you purchase your own you have to send n to them prior to installing.
I ended up bricking my first ECM. The tune file loaded and at the very end I received a checksum error. Calibrated Power was great for customer service and they overnighted me a new ECU. All in for me was 3 business days but this can be done in a day if you start the process in the morning and pre coordinate with your tuner. This link will give you a good overview of the process itself. Every tuners process will be different but if you have any questions feel free to reach out.
This will help you get the reads to build the tune files for your 22+ Cummins. This installation requires assistance so please call in if you do receive an email with further steps.
knowledge.duramaxtuner.com