in a Threat About a Family Member Putting a Lien on My Grandmas Property

My question involves real estate located in the State of: hawaii

My uncle has recently started threatening me since i am executor of my grandmothers estate as well as her power of attorney. He has offered to do repairs and done tons of work on my grandmas property without being asked and without hesitation and on occasion he would get mad and say one day he'd give my grandma a bill for all his work if she ever made him mad. Recently he wanted to update my grandmas property with being reimbursed. I said no I'm selling the property as is as I can't afford to pay him. I've also said please don't get involved any more as you are now hindering the sale. He got mad and said i was being disrespectful and that he needs to fix up the property so it would sell-again I said no thank you and he's threatening to put a lien on his own 97 year old mother's house! He has no contract or verbal allowing for reimbursement. Can he legally put a lien on my grandmas property since he did work over the years?!?

in a Threat About a Family Member Putting a Lien on My Grandmas Property