Help with family owned property

[Christopher Neal]

Hi everyone, hope this is the right place to post this question. Basically I'm looking to see what options my mother has on a property that is owned between herself, my aunt , and my uncle. 

Here's the quick backstory on the situation: My grandfather passed away in 2007 and left his estate to my mother, her sister and brother. Originally the house was to be rehabbed and used as a rental. However the house was stripped to the studs and has been left abandoned for years now. 

Last year my mother attempted to sell the home but my aunt believes the property is worth wayyyyy more then it is and would not allow the sale to happen. The house is still sitting vacant and in disrepair. 

My question is what options does my mother have as far as getting my aunt off of the title? Is it possible to sell her(my aunt) the property if shes already a part owner? Any suggestions are welcome. Thanks!