Ledge-dashing isn't too hard. Basically you smack the stick down, either lightly or hard if you prefer, but the important thing is to immediately shift your stick toward the stage [sooner the better]. That's probably the hardest part to do. Timing the waveland isn't so hard once you can at least get onto the stage from a ledge-drop. Just keep practicing that. Once you have that, practice ledge dashing. You have to crawl before you walk. You wouldn't try to waveland platforms before learning wavedashing (or maybe you would, but I think wavedashing is easier), and you shouldn't learn to ledge-dash before you can ledge-drop and get up on the stage.
The timing is tight at the start (moving the control stick from down to the stage) but after that the timing where you can waveland is actually pretty big. The moment Ganon's spinning body is on the stage you can waveland. At any point. He's never high enough that his airdodge won't move him on the ground. After you get that down you should try reverse ledge-dashing. That is much harder, but it has a similar timing. You just need to include a quick flick back (it feels like a dash-dance). You just need to get onto the stage a little farther for that.
My 30 cents.