NOTE: To be clear, I am NOT looking to use CSV export and import to change the variant names. I simply do not trust Shopify's servers to handle importation and overwrite of over 30,000 products. I also am not asking how to use the built in bulk editor to manage multiple variants at a time. (these two responses seem to be the most common when other people ask for help with this issue)
I am looking for an app that will allow me to do a bulk "find and replace" of variant name.s I have condition variants on most of our products and want to change from a "mint/Very good/good/fair/poor" scale to a "A,B,C,D,E,F" grading system. I have an app that can bulk find and replace tags, and was hoping there was one that can do so for variant names as well.
It's a year since the question was asked and I hope you found a solution. But since the questions show up in results, for anyone looking for a feature like this, please try Super Sheet, https://apps.shopify.com/super-sheet . You can find and replace basically anything in products, like this: