Legal Question in Wills and Trusts in Massachusetts

Once a person dies, their Will cannot be changed.

I want to make sure I understand your question. A will can be clallenged on a number of grounds. However, the two grounds that serve as the foremost bases for a challenge are: (1) that the person making the will lacked sufficient mental capacity to understand what he/she was doing; and (2) that the person making the will was subject to what is known as "undue influence" from persons who would stand to benefit (or whose spouses or children would stand to benefit) from a change in the will. Undue influence basically means that one person overwhelms the decision-making ability of another by duress, guilt, economic power or advantage or control of the person's finances or health care.

Both of the above answers are correct, but the most important thing is that a will may not be changed after the death of its maker. I am guessing that the 'next of kin' you mention is the executor of the deceased's estate, and they are being influenced by another to disregard the will. In any event, you should bring the relevant documents to an attorney for review and consultation.