This is really no different between switching hardware devices.
Step 1. Sign in using your existing device
Step 2. Add your new device
Step 3. Remove your old device (or keep it for a backup)
And if you feel that's going to be a big issue for you, use a 3rd party software based tool like Bitwarden, 1Password, or other tools that have indicated they'll be supporting this. That info will sync between those software based tools and allow you to use whichever devices you wish, across multiple platforms with minimal effort.
Step 1. Sign in using your existing device
Step 2. Add your new device
Step 3. Remove your old device (or keep it for a backup)
And if you feel that's going to be a big issue for you, use a 3rd party software based tool like Bitwarden, 1Password, or other tools that have indicated they'll be supporting this. That info will sync between those software based tools and allow you to use whichever devices you wish, across multiple platforms with minimal effort.