If you already managed to get the sample up and running on a STM32 target, then it will be quite easy to get access to the RTC.
I assume that you are using the template project, that you will find within the subdirectory /Examples/Template. Open the file main.c of the template and activate (un-comment) the function call
/* configure realtime clock */
EwBspConfigRealTimeClock();
That's all. Then the clock UI application will get the current time directly from the RTC via EwGetTime(). Of course, you have to set the correct time after each reset...