Recommended Steps for replacing UDM Pro with a new UDM Pro?

There was another reddit post about UDMP - Losing Connection which got me thinking I need to swap out my UDM Pro with another one. Was hoping to get some guidance on what are all the steps I would need to do in order to smoothly transition everything over to a new UDM Pro and maintain as much historical data and config as possible.

Would I have to hard reset any devices? Any specific order in which backup files I should pull and any sequence on restoring when I setup the new UDM Pro? Also, i've never gone through the RMA process with Ubiquiti, so any guidance on that would be appreciated.

Here's my current setup:
(1) UDM Pro w/ an 8TB WD Purple HDD for Unifi Protect
- UDM Pro Firmware: 1.8.4
- Unifi Network Controller: 6.0.43
- Unifi Protect: 1.16.9
(1) US-8-150w POE switch
(1) USW-Flex
(2) UAP-AC-HD
(2) UAP-nanoHD
(1) UAP-BeaconHD
(2) G4 Pro's
(1) G3 Flex
(1) G3 Bullet