Gold delivered against the futures contract must bear a serial number and identifying stamp of a refiner approved and listed by the Exchange. Delivery must be made from a depository licensed by the Exchange.
I took delivery of a platinum contract a few years ago. I used Lind Waldock although technically any brokerage can do it. A larger broker will have gone through the process many times and it may be a little easier. If I remeber right the buy/sell slippage is around 2% after all costs - which makes it pretty much the cheapest way to take delivery of precious metals. You can pay for storage in NY or you can take delivery in person in many major cities. Just contact a large futures broker and they can run through all the current costs with you - don't forget the re-assay fee when you sell back.