A pill splitter available at any pharmacy does a fine job of splitting alprazolam xr. I'm Rx'd 4mg/day and often only take 3.5mg/day if I don't feel the need for my full dose and to build up a bit of a surplus for really bad days. FWIW, I get 1mg Aurobindo pills now that are yellow with an "x" on one side and "73" on the other.
At my dose, I don't have to worry about my level getting too low under most circumstances. I'd be careful with lowering your dose if you dont have a dose sufficient to keep it in your system for the full time you need it. Mine are supposed to be taken 1mg p.o. 4x/day and they're supposed to last 12 hours, so even if I take a lower dose, I'll have alprazolam in my system all 24 hours of the day even with a slightly reduced dose.