You can't change the theme for one page in an application. As the theme is an application setting.
You can how ever change the template the page uses.
If you want to use a page template of an other theme you have to copy that template to your current theme.
Make sure that the references to the css files are still accurate.
Depending on the theme the CSS files used could be defined on the theme level. If this is the case you have to change that and define theme at the template or even page level.