Send new version of fba stock (PL) and recall old without mixing

I have a product that I need to recall and send the new version. Its a private label product. The existing one is using the asin barcode (B00..) when we send it in.

I want to create the new listing and send stock quickly without mixing with the old one. What’s the best option… new listing under same asin and send using X00 code? Or new variation ?