To replace low voltage switching to line voltage switching could become a big job. New line voltage wiring has to be installed from the existing switch box to the low voltage relay. At this point the new wiring will be spliced into the wiring where the old relay was removed from. This splice connection has to be done in a junction box that has accessibility as defined in the electrical code book.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized
IF YOU ARE NOT REALLY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.