Sometimes moves are made for us, no matter how much we want to do them. If you're spine hurts I'd definitely take the leg drop out of your repertoire. (Most of the time it's the tailbone) Now if you're adamant about doing this move and the video tips don't help. Your best option is to start doing squats to build your glute muscles. This will add padding and help with your spine issue.
I remember guys like Bret Hart and X-Pac used to do these really fast low-angle leg drops. What would be the approach for that style of leg drop as opposed to the jumping sort? It seems the timing would be way more of an issue.
Pro Wrestling is pretty much a brand. But let me ask you this what kind of leg drop were you thinking of doing in a Greco/ collegiate match?? We'd love to know!