Can the executor of an estate enter an occupied house without permission, take what he wants, and change door locks?

My partner and I (him male; me female) lived together for 19 yrs. He passed away 2 weeks ago. He had a will. He named his son Executor. Within hours of the death, the son came to our house (partner and I co-own the house) and started looking thru my closets for his dad's hand guns. Within a few days, he also removed (with my knowledge but not my consent) all of his dad's valuable tools (partner thought they would all sell for approx $40k) and about 12 rifles. Has also taken a Ford pickup for his son (which was in accordance with Partner's wishes). Has also removed a computer and all of Partners files, some of which contains my personal info. I read that he has the authority to change the locks on the house. This doesn't seem right. It seems like I should be the one changing the locks since I'm still living here. Today he asked me to sign a paper acknowledging that he's the Executor. Once I do that, does he have greater rights regarding access to my house and its contents? I feel like I'm being taken advantage of, yet he said to me today that he doesn't know what I've already taken (nothing) and doubt's that I'll be truthful about the ownership of our personal property. Obviously he doesn't trust me, even though he's the only one who has taken things. Should I meet with a Probate lawyer to clarify what rights I, as the current home owner, have?