How would you use a fixed pulley to lift something heavier than yourself?

You have to have the right size pulley for the weight of the object you want to move and a secure place to attach it. Then, once it's all hooked up, you'll need to generate the force to pull on the rope or cable that will then move your object. If it is more than you can produce with your body, you can attach an engine to it and let it do the work.