Can this be done? Is so, what strings/gauges are recommended and does the nut need modification?
Thanks

I guess this question may be better suited to "setup and repair"-Mods feel free to ove it (I don't know how).

Standard tuning is G-C-E-A, so just adjust the strings to sit as E-A-C-G, and tune the C to D... actually... come to think of it, I'm not completely sure if this will work on a baritone. I only have had experience with sopranos. The only problem you may run into is the affect of the tone of the strings. I mean, one your A might be higher in pitch than your E for example... but it's a start.