How to install 140mm fan in PC? I'm sure it will be easy, but how do I avoid static damage or shocks from PS?

I have an anti-static wriststrap. One end goes around my wrist, the other end has two options for attachments... 1. an alligator clip that you can clamp to the computers frame for grounding, and 2. an input plug that looks like it could fit in a headphones jack.