OK, it stopped raining!
Here's a photo of the angles I use to get it in:
Hitch Bar Install
Turns out I don't really tilt the top pin back toward the truck. But the whole bar is angled toward the truck and down to the ground as in the picture. I can then insert the lower pin into its hole and lift up on the chain end of the bar to get the top pin into position. Then rotate the chain end of the bar back to the trailer.
Hope this helps.