Lawyer up....its going to be one hell of a ride.
My dad was pardoned by Lingle for something and moved out of state back in 2008, where he purchased firearms in his new state of residence with no problems.
In 2010, after 2 years of purchases, HPD flagged him in NICS for the conviction he was already pardoned for, because THEY felt Lingle's pardon wasn't specific enough. This caused him all sorts of problems, and he was forced to surrender his firearms to an acquaintance by the ATF because of HPD and the State of Hawaii. Because of this, he had to start the whole pardon process again for this specific incident, which must start at the bottom and work its way up to the governor.
My dad died last year, and still hadn't received his pardon, even though it was sitting on the governors desk waiting for signature, with recommendation it be signed by both the investigators and the DA.
You can either listen to people who have not gone through this process, or you can listen to someone who had helped someone go through the process. If you want to wait around for 3-5 years MINIMUM (no joke...the DA was quoted that the process takes a minimum of 3-5 years for the POSSIBILITY of being pardoned), then have fun. If not, lawyer up and fight for your constitutional right.