Do not use a razor, elect for the epilady hair removal tool.
If you do not want to shave and still want to go hair free, melt some wax, dip your sack in it, let harden then slip it off for a nice smooth appearance without any worry of nic's or ingrown hairs.
Yes.. and get ready to cry for a week or two.. myyy.. i can only imagine how bad thats going to hurt..
but there are better things to do.. usually you dont get a lot of hair on your balls.. just go to places like
http://www.global-electrolysis-supply.com/ buy yourself a cheap 50 dollar electrolisis machine.. kill those hairs.. then trim them.. and soon your balls will be shaven forever.. this is the best thing to do.. no pain at all.. and its just forever.. it looks like a baby's ass after 3 or 4 months