1) Have a bad idea. Or if you aren't a Wikipedia editor, go here.
2) Ignore community input. Repeatedly.
3) Do said bad idea.
But don't worry, a bunch of us are working on slapping back some sense in the Wikimedia Foundation. Hopefully these awful (and can you say arrogant and self-absorbed!) messages will be gone soon.
Update: The banners are now down due to technical problems. Hopefully since there's a technical delay and a huge backlash, the WMF will consider the several alternatives proposed by volunteers. More as it develops.
• Phoebe, Ragesoss, Pretzels (11 November 2009). "Controversial 'Wikipedia Forever' fundraiser to start 10 November", Wikipedia Signpost, 5(45). Accessed 11 November 2009.