static boolean unregisterJar(List<String> jarsToUnregister) {
    LogHelper console = getConsole();
    try {
      Utilities.removeFromClassPath(jarsToUnregister.toArray(new String[0]));
      console.printInfo("Deleted " + jarsToUnregister + " from class path");
      return true;
    } catch (IOException e) {
      console.printError("Unable to unregister " + jarsToUnregister
          + "\nException: " + e.getMessage(), "\n"
              + org.apache.hadoop.util.StringUtils.stringifyException(e));
      return false;
    }
  }
Reload the jars under the path specified in hive.reloadable.aux.jars.path property.

@throws IOException
ql/src/java/org/apache/hadoop/hive/ql/session/SessionState.java