Bulk Import Carrier Information on Product Import csv
Currently you can import the weight and dimensions of an item but not its carrier. The only way to change a product's carrier is by searching for the individual product in the product database and changing it's carrier one-by-one for every product. Specifying a carrier for all your products will take a lot of time.
Using a csv product import for the carrier would save a lot of time which is valuable to us all.