A trust was created by will for the benefit of A. The trustees are B
and C. That's B AND C, not B OR C. The will does not specify what to
do if B and/or C cannot serve or don't wish to serve. B is elderly and
wants to pass the duty to others. C is elderly and may become disabled
very soon. Please supply the text of a document that B and C could
sign to appoint new trustee(s), and please supply the text of a
document that B could sign alone (along with a letter from C's doctor,
I presume) if C becomes disabled before a document can be signed
together. If it matters, A, B, C live in KY and all financial
institutions that will receive the document have offices in KY. 

I realize that the financial institutions may ask that their own
trusteeship forms be signed, and I'll be collecting those blank forms
while you're generating generalized texts that may have to suffice.