I used a heavy hand truck (and some young strong backs) to position the barrel under the windlass.
I took an empty barrel, offloaded the old chain into that first.
BTW, I have 350' of chain as my primary rode. Sure, it's heavy as hell, but the boat weighs 96,000 wet, and nothing is as secure as an all chain rode.
I have a 500' nylon rode with 75' of chain as a secondary.