Propane overfill by a "professional"

I would vent or burn off to get 80% of tank capacity using weight method. I would also burn off and not vent because neighbors will think there is a "propane leak" if you vent. And burn off excess with something that puts out big BTU's, so your not doing it all day. I've have one of these http://www.amazon.com/Hot-Max-500G-Propane-Torch/dp/B00282LP34 found it great for different things around home. Great for weeds on gravel parking spot. Even starts a campfire so often. But it does sound like a rocket, it puts out the BTU's.

As a comparison a "torch tip" I use for soldering or thawing pipes around the house, took 7 hours to empty a 1 pound bottle at 55 degrees at sea level.