Reset custom page skin to global skin

I added custom css at the skin options to several pages to change image positions. no i realised this was a bad idea, because now are global changes of the custom skin take no effect to these pages. so i want to add the css in a html block to these certain pages. but how can i reset the skin of these pages that global skin changes take effect again?

If you changed the skin on specific pages, you should be able to change it back to the original skin and save it and be all set I think.

The thing is, that i don’t use the original skin. I use a quite modified skin and need actually an easy way to reset not to the original skin rather to the global skin.
But i will try if setting back to the original skin, it is easier to get to my global skin.