The question is quite brief to understand the situation.
The professional consultant can only help you for the way out after understanding the whole issue.
In case of corporate structures like a company or LLP - the majority stakeholder may take the matter in hand as per the previous agreement.
For a voluntary partnership as well, there is surely an agreement in place. You are required to refer the said agreement to find a way out.
Any way, you need to consult the professional with details of the matter and find a way out.