Small changes like changing a variant name can be done by following simple steps as below.
Step1 :- Go to “Inventory Overview” where all your products are listed and click on the product whose variant you wish to modify
Step2:- Search item in the search box and click in the Edit option for the respective item
Step3:- Tap on the Variant name as shown on the above image
Step4:- Select/Un-Select “Online Flag” to make the variant online or offline. Once the changes have been made click on “Save Changes” to finalize your changes.