Yes, the gauge was that easy to replace. Turned everything off, unscrewed the old one, screwed in the new one with some Teflon tape wrapped around the end.

It's reading - but the needle continually vibrates between, say 12-15 psi. Is it supposed to do that or is the need supposed to point to a specific number? This is just my second season with the pool. I never saw the old gauge work.