You don’t need any guide. Just follow the signs “elephant trekking” and put your scooter at a parkingplace. You’ll see a walking path and you wil probably find your way to the waterfall.

Not strenuous at all! Just prepare to cross the creek and rocks a few times. I did the hike barefoot, in fact!

You could of course go with 2 scooters or rent a tuc tuc or taxi (the cost will depend on the distance to the waterfall).