Takes about a year, although the process is a bit accelerated for Americans stationed in Germany. Call it 6-9 months, and it is quite involved as Ben alluded to. Lots of book and classroom study, the "hands-on" has much to do with customs and the process of the hunt. It's not grab a gun and head to the woods, it's a great deal of planning and organizing a hunt.
I started the process, but the demands of the Army left little time (and lots of conflicts) with getting my license. It was easier and cheaper just to go shoot Trap and/or Skeet at the Rod and Gun Club on post then take leave to go back to the states for Deer Season.
https://grafenwoehr.armymwr.com/programs/hunting-fishing-sport-shoOh, but to get back to the dead bison. Apparently, there are large(ish) herds in Poland and other Eastern European countries. This one managed to sswim the Elbe it would appear. It's not like they shot the very last one.