One of two ways:
1 - Shackle ~18" of slack chain to the hook in the bottom of the chain storage
locker (where the bitter end is connected) and run the windlass paying out the chain. When the 18" hits the shackle, it'll break the drum loose.
2 - Put the handle in one of the holes on the drum and do the same as #1, run the windlass (paying out, not in), when the handle hits the bulkhead it'll pop the drum loose.
Do not use the chain gate/pin under the windlass for #1, don't ask me how I know not to do such.
The drum tightens up raising the chain, hence you need to break it loose paying out chain. It's a little scary the first time you do it, but it does break loose. And yes, the handle will bend trying to break it loose by hand, but it withstands the bump at a faster speed.
FYI, I had to replace the clutch
face after getting caught in fast current
with the anchor
in rocks. It broke the plate from the shaft. Hopefully you find everything in good shape.