I don't know about the RI, but you don't need humidity at 80% for shed. I'd drop it down to between 60 & 70. Unless it's high because of his RI.

It will probably take about a week. Here is a sticky on the shed process: http://www.ball-pythons.net/modules/...warticle&id=57

In my experience too much humidity can cause the shed to tear easy.