Hey Doug,
if you have a bolt the right size for that nut, set the bolt in, then use a small puller kit through the back end of the socket - some plumbing supply places will have a faucet puller that will have a threaded center that should get through the hole on the wrench side of that socket.
Or, really, if you've got a bolt long enough, keep driving the bolt and use the end of the bolt to push the socket off the top.