Hmm.... let's see if I can dumb it down some more for you...
It's about the same as...
Put up, or shut up!
When the going gets tough, the tough get going!
If you can't hang with the big dogs, stay on the porch!
Lead, Follow, or get out of the damn way!
If you can't be part of the solution, don't be part of the problem!
You see, in Alaska it gets really cold, but there is often work that needs to be done outdoors. (work is something people often do, who aren't dependent on the gub'ment like you) So anyway, it takes a tough person to do the work in the bitter coldness of Alaska, and some people can't handle it. So they came up with this saying, for when they go out in the truck to do a job. Buck up, means to "get tough" or... stay in the truck (where it's warm) because you're a pussy who can't 'buck up' and get the job done.
You know, it's really hard to imagine someone so profoundly stupid as to not understand what "Buck up, or stay in the truck" means, and needs to have it explained to them like a kindergartner. Prissy, is your mental state worsening, or do they even test you anymore?