Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
NumPad1: Freeze Health
NumPad2: Freeze Stamina
NumPad3: Freeze Warm
NumPad4: Freeze Hunger
NumPad5: No Building Costs
NumPad6: Unlimited Items
NumPad7: Unlimited Skill Points
No Building Costs: While active you can build/upgrade everything for free. You also don't need to have the required materials.
Unlimited Items: While active items will not removed on use.
Unlimited Skill Points: First make sure you have NOTHING in your quick slots! Also make sure that you stand right in front of your shelter and inventory and so on is closed. Activate this option and access your shelter and spend skill points. Deactivate this option IMMEDIATELY when you are finished. DO NOT use this option ANYWHERE ELSE as it will affects other things as well then.