States: New York: Otsego
The registrar of wills in Otsego County is the Surrogate Court. Check with that county's genweb page and there is probably an address there. (www.rootsweb.com/~nyotsego) If not try a search on Google.com for Otsego County or for its county seat, Cooperstown.
Be advised that state law allows the Surrogate Court office to charge a researcher a hefty fee to look up a will for him. It can be upwards of $75 plus copy fees per page. A local researcher, or yourself if you can make it there, could probably find it quickly and for less, or check with www.sampubco.com and see if it is available through that company.