It's a little intimidating the first time.
But, it's not big thing.
Use a mach 3 and either edge or skintimate shave gel.
Just lather up and shave away dude. Don't be scared to pull or hold your sack at the right angle to help shaving.
I have never cut my nuts or turned them in to a "bloody mess" with a razor. I have howerver nicked my sack with electric shavers and they did bleed.