Just took mine off with impact and didn't damage threads. You're more likely to damage threads by hammering on a punch in this area, not necessary at all.
Staked Nut
Informative write up, however you do not have to make special tools to unstake the nut, just put an impact on the nut and it spins right off, or use a breaker bar if you don't have an impact. Using an impact wrench wrench allows you to avoid securing the transfer case output flange...
