My aunt was primary owner of our family house and under her came me then her brother. Another brother was granted life estate. Now my aunt passed and I took over the maintence for the house. If I were to buy her brother out of his share, what happens to her brother with the life estate? Can I make him leave or be responsible to share-bills. Can I even sell?

A life estate affords the holder the right to live in the property as long as they live. You can certainly buy out the other part owner(s). But the life state will remain.

You can sell but subject to the life estate.

Ukarican, you are not making a lot of sense.

The aunt was "primary owner"? In other words, she owned it, subject to the life estate (she having a remainder interest after the death of the life tenant)?

And what do you mean by "under her"? Did she leave it to you and her brother (your uncle or father)? Was her estate admitted to probate? Or was there some sort of a trust or joint tenancy, with regard to the remainder?

I don't understand why you took over the maintenance of the home. Normally, that would be up to the life tenant.