First of all you need to go into the plant room inside a building.Then keep your distance from the exit door cause thats where he will pop out.Then you need to attract him by moving or firing your gun.Once she gets away from the door go through and stop because she will come through the wall in front of you and automatticly and kill you if you run into her(trust me i did it before).you have to do that twice then you will run into a room with pillars and a giant tree in the way.Don't wory some bats will move and the beserker will try to get them.Once you get past her try to make her destroy all the pillars then it will break the glass and you can use the hammer of dawn to destroy her.