Can I reinstall this gasket if I remove my header?

No. Exhaust gaskets are crush-sealed during first installation—reusing one will leak. Always install fresh when you pull the header off.

Do I need any other gaskets or seals when I replace this?

This gasket seals the header-to-engine interface only. Check your full exhaust system for other leak points (downpipe flanges, cat converter joints) while you're in there.

What tools do I need to swap this out?

You'll need a socket set and basic wrenches to remove the header bolts. The actual gasket swap is straightforward—clean the old gasket material off both surfaces with a gasket scraper before installing the new one.