Here's how to handle those big guys with a stealth approach first you'll need to grab the executioner skill from level 3 of the melee tree, since that's what lets you actually do the takedown. Once you've got that sorted, the process is pretty straightforward but timing is everything

The trick is catching them when they're distracted, usually when they're searching around on the ground. That's your window to crouch and sneak up behind them and when you get close enough, you'll see that triangle prompt appear. Just remember, if you try this without having executioner unlocked, you're basically asking for trouble since they'll spot you and, well, that's not gonna end well

Something interesting to keep in mind these guys have pretty predictable patrol patterns when they're searching, so if you're patient and watch their movement for a bit, you can usually time your approach perfectly. The whole stealth kill thing is actually super useful for clearing camps without alerting every freaker in the area