Resident Evil Zero Walkthrough #4
The Factory

Walkthrough #4 - The Factory

Arriving to the factory using the Cable Car, make your way to the Panel Room and pick up the Factory Map (Follow the directions on the maps)

Exit the room and use the platform to get down

Keep going forward to pick up the UP Key

After picking the key, 2 Lizards will show up on your way to the exit;
dodge the first one and shoot the second one with a shotgun once to clear the way (no need to kill it);

Go to the Panel Room again and use the UP Key to higher the Turntable

Save the game then go to the Turntable and lower it

After reaching the bottom, pick up the Elevator Key

Use it to activate the elevator and get ready to fight The Tyrant

The way to deal with the Tyrant is to stay behind him at a long range and shoot; when he turns and launches at you just dodge to his left side to get away from the claw on his right arm;
Keep doing this until you defeat him.

Here is a video showing how to defeat the Tyrant using only the Handgun while taking no damage:
Youtube Video

After defeating the Tyrant, get in the elevator
LV 1 will take you to the Training Facility where the train crashed.
LV 2 will take you to the Factory where the Cable Car stopped. (You find supplies on the way)
LV 4 will take you to the Treatment Plant where you will save Billy.

Go to LV4 and you've cleared the Factory Stage.

Next up, The Treatment Plant.