The New York Times says that it's easy - I suspect that it is not so easy, but perseverance pays off.
I read the article and what I took away from it was that in most of the cases cited, the judges and/or prosecutors did not do their jobs very well. There wasn't any reference to states like mine (Idaho) that task the parole and pardons board with the responsibility of hearing gun rights restoration petitions, probably for good reason - that bar isn't "easy".
The authors have an agenda, of course. They've cherry-picked the worst-case scenarios from whatever data they've accumulated. They've avoided directly drawing a conclusion, but cast certain organizations as something approaching villains.
Well we don't rent pigs and I figure it's better to say it right out front because a man that does like to rent pigs is... he's hard to stop - Gus McCrae