If you need to disable any variation(s) in variables products you can do next:
- In the Filter select product type 'variable' and click on 'Filter' button
- On tools panel enable switcher 'variations'
- Now you can select (using checkbox in the first column) products variations which you want to disable OR if you have a lot of such variations in tab Bulk Edit check post status and select there 'Private'. Of course if that variations belongs to the products which belongs to any category or any another attributes you can continue with filtering of variable products to avoid looking them in all variable products in the shop - so if you can use Filter for targeting - use Filter.
- Now main thing: select on the top of tab "Bulk Edit" all combinations of variations you want to disable using button 'Add attributes combination to apply on': select attributes you need and then if you going to disable 2 combinations click on that button 2 times, and in generated drop-downs below set combinations.
- After checking twice that you did all right click on 'Do Bulk Edit' and wait while operation will be finished
- If you decided that you did smth wrong - you can roll-back operation in tab History