When swapping out a hard-wired Sonos product, make sure to add the new Sonos product to your Sonos system before swapping out the units. This will ensure all settings will be transferred over to the new product. The following steps apply to all Sonos products: Boost, Bridge, Play:1, Play:3, Play:5 (gen1 and gen2), Playbar, Playbase, Beam, Connect, Connect:Amp and Sub.
If your currently wired Sonos product is no longer operational, you can wire in any other existing Sonos product to your router to regain system connectivity.
Plug the new Sonos product into power and add it to your existing Sonos system by selecting Add a Player or Sub, or Add a Boost or Bridge, from the Manage menu on your Mac or PC. If using a mobile controller, these options will be found under Settings. It is not necessary to plug an Ethernet cable into this unit yet as there should be another Sonos device still wired into your router.
Step 2: Once the new Sonos product has been added and updated, disconnect the Ethernet cable from your wired Sonos product and connect it to the new Sonos product.
You can now unplug the Sonos product and move it to another area if necessary. You will probably want to rename it using System Settings -> Room Settings -> [Choose the Sonos player] -> Room Name.