Will this work with my factory wiring harness?

Yes. This assembly plugs directly into your existing brake light connector—no splicing or new harnesses needed. Plug it in and you're done.

Do I need to remove anything to install this?

You'll need to remove your current center brake light assembly. Unclip or unbolt it from the factory mounting points, disconnect the plug, then reverse the process with the LED unit.

What's the actual lifespan of the LED compared to the stock bulb?

LEDs last significantly longer than incandescent bulbs and won't burn out from normal use. Exact lifespan depends on duty cycle, but you're looking at years of trouble-free operation versus the occasional replacement bulbs require.