Let say you want to import the product from AliExpress and It has 5 variations. If you hover your mouse to some variation (on AliExpress website), you will see its text representation as text hint. It’s shown in the screenshot below. As you can see the text hint for the second variation is “2” and it’s not clear enough. We guess you would like to have the “black” value instead “2”.
You can set the necessary value in the Import List when you add the product into it. The following screenshot illustrates that.
Once you added the product into the Import List, just open the appropriate Variants tab and change the values for attributes as needed. When you push that product into WooCommerce, the customized attributes will be added to the product and the changes will not be reset during AliExpress synchronization.