I did my first split rings on spinner blades last night. Yes, it was a pain but I learned a few things to make it easier.

First, I used the edge of the spinner blade closest to the hole to open the split ring. Once open it was just a matter of turning the blade to draw the ring through the hole. If I moved the blade about 1/8" further into the split ring it created an opening wide enough to slide it onto the jig swivel. The trick was to steady the jig swivel by clamping a hackle clamp to its edge. Once I had the split ring in the swivel eye I used a tweezers to rotate it.

Of course, all this was done with the aid of a swing-arm lighted magnifier on my shop table...the greatest invention since sliced bread. I doubt this would work with a hook since it doesn't have the fine edge that the spinner blade has.