I'm pretty sure you can set the hours with the main maintenance password, rather than a second-level password (which you have to call EI for and are single-use).
EI's tech support is excellent (though it varies a little depending on which tech answers the phone; Dave A is the best one). It's a very complicated system, and expect there to be at least a couple of errors in the setup that EI sends you (usually easy enough fixes, but don't assume that they got everything perfect). I installed a 3-screen setup in my twin myself, with my A&P supervising. It's a whole lot of work. But once it's working, it really is awesome. The little red connectors they send you are good for the probe wiring, but anything else I used butt splices. After you do the first install of the probes with the red connectors, make a note to go back a few days later and tighten them all up again; inevitably a few will be loose and they'll lead to erratic CHT/EGT readings.