如何更新服务器缓存的CSS ?

I have just launched my new rails site and there are come CSS things that I need to change but i think that the CSS caching is keeping my changes from working. Is there a way to clear out the cache? What am i doing wrong? Let me know if you need more information (i couldn't think of any code that would help you) and thank you very much.I have just launched my new rails site and ther