Dispute

I have a land contract with gasp a family member. They have taken the garage doors off over 5 months ago and are refusing to put them back on. Also we got a threatening email saying they were ripping the doors off a shed on the property that houses some of our belongings. There is still some belongings in the basement that are ours we are trying to get out and the garage. Said family has threatened to remove and through out our possessions with another family members help. Is there anything that we can do about, the threats? The garage doors? And the fact they put direct t.v. on the house without clearing it first? Thank you in advance.