My brother is telling me and my 2 siblings that we have to do this and do that. Remodling a garage office and other things, so that he can buy it. He is spending the estate money to do this, none of his own. What can't an excutor do?

Did a parent die? If so, was there a will, and what did the will say about distribution of the estate?

Most renovations don't increase the value as much as was spent. So I would tell him that you and your other sibling want the house put up for sale as is, and hire a lawyer to fight him if he refuses.

And the "so that he can buy it" is troubling also. If the personal representative expects the OP to remodel a property belonging to the estate and then intends to sell it to himself, this convlict of interest needs to be addressed.

Did a parent die? If so, was there a will, and what did the will say about distribution of the estate?

Yes my father passed away. My mother died many years ago. The will states that everything was to be sold and the monies divided 4 ways.