1. Bring up the console with "F3" or "~"
2. Type Open KF-Biolapse?Difficulty=0?Gamelength=0 then press enter (Normal Difficulty - Short Wave)

3. Select Berserker

4. When you spawn, look at the trader distance and mark.
If its around 285m and the arrow is pointing upwards, that's the area for Blender.
If it's not, Goto the console and type "Open KF-Biolapse?Difficulty=0?Gamelength=0" and try again.

5. Once you get to the area, full buy 5 emp grenades, no need for any weapon.
ALL YOU NEED IS THE EMP GRENADE ON THIS ONE.

6. Here's the Area (don't use bash or any attack, only emp grenades)
Up ahead is the blender passageway (be careful, you can be killed by falling to the blender)

7. Gather zeds by circling around the area here.

8. Once enough zeds gathered, move to this spot and crouch there. Don't get pushed off and stay to it.

9. Once you're in and zeds are attacking you, throw an emp grenade on this spot. Wait for it to explode.

10. Once zeds are in panic mode, try to jump over and avoid them. Don't bash or any attack, just evade.

11. Watch zeds fall to their deaths on the blender.

12. Once away, repeat Step 7 and do it until you get 20 kills. If one game isn't enough, redo again.

1. Same with the start point. Trader area should be around 687m.

2. Go to this area below the stairs.

3. Wait for zeds and gather them all together.

4. Once the trap doors are open:
Zeds must be on exact trap position. once you pressed the button, only the zeds who stepped on your trap will trigger the objective, don't let the other zeds fall to the opened trap door, it will not trigger the objective
DOOR LASTS FOR 10 SECONDS DURATION.
Cooldown after the door is closed was about 1 minute and 25 seconds.

5. Try to loiter around the area and come back to the trap door afterwards.
Repeat the steps.

6. That's it, you're done.