Urgent my website is disabled by template installation; Skaywalker can't help

Hi, Urgent my website is disabled for 24 hours, by template installation; Skaywalker can't help me and I need resolved it. The error:  

<h1>Internal Server Error</h1> The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error. More information about this error may be available in the server error log. Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request. <hr />   <address>Apache/2 Server at www.aprendematematicas.org.mx Port 80</address>