The cutting out the meaty bits and chopping it into small pieces part was correct.
Sounds like the heat wasn't as low as you might have thought. Does it taste burnt? If not, I'd still use it, but either try a wet render next time, or back off on the heat. It should take a long-ass time (that's a scientific measure of time if I've ever heard of it) to dry render. You should get a bit stir crazy and be really tired of standing in the kitchen by the time it's done. At least that's been my experience.
Wet rendering, on the other hand, takes several forevers longer and should only be done in a crock pot while you're out camping/hiking/biking/practicing karate in the garage with your step brother.