Where to Clear WP Super Cache?

I received an error.
WP Super Cache is not properly configured to work with Simple:Press. Please visit your WP Super Cache Settings Page and in the Accepted Filenames & Rejected URIs Section for the pages not to be cached input field, add the following string:

/forum/

Then, please clear your WP Super Cache to remove any cached Simple:Press pages.

I added /forum/ where do I clear WP Super Cache? I cannot find a “Clear WP Super Cache” anywhere.

http://wordpress.org/extend/plugins/wp-super-cache/