[Q] LG G3 stuck at firmware update topic

My wifes LG G3 got the lollipop update (I presume) but it got stock at 22% at the firmware update screen. After 2 hours my wife apparently got tired of it and took the battery out. The phone now repeats the procedure on boot and instead gets stuck at 23%.

What can be done here? Stock unrooted.

ps: googled for a good 15 minutes before posting but found little information on what to do.