In this scenario, there are two options:
- manually provide overrides for the scheduler styles
- change the selectors of the inherited styles to more specific ones
Since you are interested in option 1 - if you have only one instance of RadScheduler, you could modify its CSS files (something like a custom skin) to have ID-based selectors instead of class-based, thus increasing the specificity of the selectors. For example .RadScheduler will be translated to #RadScheduler1.
the Telerik team