The answer to 'how to replace ceiling fan installation' is to safely remove the old ceiling fan and install a new one. First, turn off the power to the ceiling fan at the circuit breaker. Then, remove the old fan by unscrewing the mounting bracket and disconnecting the wires. Next, install the new mounting bracket and connect the new fan's wires to the corresponding wires in the electrical box. Finally, secure the new fan in place and turn the power back on to test it.
It's important to follow the manufacturer's instructions carefully and use proper safety equipment like gloves and a ladder. If you're not comfortable working with electrical wiring, it's best to hire a licensed electrician to do the job.