HE HAD A PHONE!!!!
Take a picture of the sodding combination lock, send it to Bill, Bill tells him the current setting, and by feel he clicks up one, down three, up two...
The plot of the last two episodes has made The Flash plotting team look competent by comparison. I felt a bit embarrassed watching it, it was so stupid.
It's such a shame, as it's such a jarring dip in quality in an otherwise good season, and specifically coming after such a really great episodes.