Setup fails on "Wifi is connected"

My YI Home U hangs on “Wifi is connected” during setup.
How can I do a manual firmware update?

Customer satisfaction is a priority for Kami Home and we provide 24/7 customer support to our users. We regret that you had an unpleasant experience. Please reach out to us at the email listed below so our customer support can help you out:

Just so you know there is no support at Yi… The reply you received from support above is just lip service so everyone on these threads think Yi is going to try to help. You will see they just send you canned replies while trying to get you to subscribe to their cloud service. If you are within the return period… return these useless pieces of plastic. Good luck