I use a 6ft x 1 3/4" solid metal bar to ram down into the ground and each time wiggle the bar about to make the hole bigger , then when deep enough just put the post in and whack with a maul . You could also get a manual post knocker to use instead of the maul , the type that is a 6" or so pipe with one end closed off and handles both sides , you then place it over the post and lift and drop HARD !!!!
But if your ground is frozen more than say 6" down ....I doubt you will get them in by hand anyway.
I have never used the powered auger type of hole borer . Seeing a bloke spinning round on one , hanging on for dear life , somewhat put me off the idea.
cheers
Russ