Complex sentence: However, in April 2014, changes were made to the calendar including dropping Rio de Janerio (which already replaced Hong Kong) which the replacement is yet to be announced and will take place on February 14, moving the Los Angeles round to April 4.
Split into simpler sentences: However, in April 2014, changes were made to the calendar including dropping Rio de Janeiro, which had previously replaced Hong Kong. The replacement race is yet to be announced and will take place on February 14, moving the Los Angeles round to April 4.