Things You'll Need
Instructions
Hide from The Boss and wait for her to come to you.
Counter The Boss's CQC (Close Quarters Combat) attacks by pressing the "Circle" button at the right time.
Attack The Boss with a powerful gun/weapon or your fists (if defeating her using stamina depletion) to knock her to the ground. If you're not going for a win using stamina depletion, shoot her in the head to do more damage.
Shoot The Boss in the head with any weapon while she's on the ground. Use the MK22 tranquilizer gun if you want to win using stamina depletion. Most other weapons (guns and explosives) will damage her health meter and kill her.
Repeat this process, healing as necessary, until you finally defeat her.