joint ownership problems

minnesota
my four brothers and myself inherited 160 acres from my father jointly. Only my one brother farms the land next to
this acreage. He made me an offer to purchase my share in
early January and requested a letter be sent indicating my
agreement to sell to him. I did this as requested.
He has since then made one excuse after the other not to complete the sale.
At the time we inherited, the lawyer had mentioned that we all had to agree unanimously on every little thing and he suggested that this would not work with so many owners. He highly recommended the land be sold. My brother had been renting this land from my father and without a word to any of us simply stopped paying rent...even though the lawyer had set up an account for the rent to accumulate until probate finished. He has now made it quite clear that he intends to not follow through with the purchase nor pay rent. Can I force the sale of the land and/or stop this nonpaying rental insisting it be rented to someone else.

[HomeGuru]

Yes.

Minnesota
Not really wanting to cause family problems, I would like
to leave him an opportunity to come to his senses. What would be my proceedure to force the sale or stop his non paying rental. Could this be accomplished just with registered letters
Sorry to be such a nuisance

[HomeGuru]

Court action needs to be taken.