First Part, Spider Specimen. You need a spider to trap inside the cage. Cage are located inside Lab “A”. In order to work this cage, you need to turn the power. Then, go into the panel and press “F” (PC users) to lower it down. Once its down, train the spider into the cage. Next, raise up the cage and wait for the machine to be finish. Once its done, your first part will reveal.
Second Part, Special plant. To get this, you need to turn ON the power. Then, go inside the bunker straight towards to the operating room. Now, on mule kick perk. You will see a room that is full of water. Swim all the way down straight to the bottom and your part will be there.
Last Part, Green glowing zombie. This zombie will spawn in any round. Once you see a zombie that has a green glowing orbs in his pocket. That is your last part. Note: Don’t run away from him or you will end up waiting again in diff rounds.
Note: This can be done in any order