Let's say you have built 5 shipping methods with custom settings on prices and different countries in different zones and put quite the effort into making your shipping rate as you need it to be.
And now you wish to change the carrier and replace it with a new one.
Do not worry, this is easy and will not require much editing from you.
1. Create your new carrier in Settings > Connect to Carrier > Save credentials
2. Go to your existing shipping method and update which carrier you wish to use
3. Also remember to update which service from the carrier you would like to use
4. When the carrier is changed on the shipping method, please also ensure that all your add-on services also are updated such as paperless, ship with care or other.
Everything else will remain the same and will not require any editing.
Your Shipping method ID, prices, zones, notifications, and countries will stay just as they are. This is valuable if you have a third-party integration that relies on your shipping method ids.
Alternatively, you can also duplicate a shipping method, however, this will create a new shipping method ID. Read more here about ID's
If you want to read more about how to set up a carrier or dont know how to find your shipping methods and rate, then read more here