People who have switched their hours from the traditional 40 hour schedule, how did you bring it up with your manager?

Background info: I work in the Business Development office of a small local bank. In the office we have the director of business development and 3 employees below him, including me. As a team we largely work independent of the bank and function on our own timelines. We work 8-4:30 M-Th and 8-5 on Fridays, the same hours as the bank. There is no reason for us to be open these hours as long as we have some overlap. There is also no reason for us to all be in the office at the same time. We rarely are.

So the 2 other employees and myself would like to breach the subject of switching to 4x10 days and alternating days off so that 75% of the office is always present. We know the director of business development would be all about the idea but don't know how to talk the CEO into it. We suspect he will think this is "unfair" to the other employees and say no. (Even though IT already works remotely on some days and there's been no uproar about that.)

Those of you who have successfully negotiated nonstandard work days, how did you approach the subject?