Hi there, I'm in need of some advice.

So recently my mother and I have come into my late fathers business as new owners and directors. My mother inherited the business as well as my late fathers shares (75%). Before my father had passed, he gave shares (25%) to a director that he had appointed. The issue we are now facing is that the minority shareholder/director has taken on the 'boss' role and treats the business as his own.
We have a lot of concerns with regards to business practices in place, and we want to do as much research as possible into our rights as majority shareholders and owners of the company and all the legal avenues we have to protect us and my fathers legacy within this business.
Some employees have come forward in private to let us know about some of the malpractices taking place, such as potential employee poaching.
How can we comfortably take back control over this business? I do not want my fathers legacy to be lost, and I intend on running this business for many years to come. It is a very tricky situation and we have been patiently working on it for over a year now, but I still feel as though there is a lack of trust and I am honestly worried that if we divulge too much information or make any threats etc the director/minority shareholder may try to sabotage the business.

Any and all advice would be greatly appreciated!

Thanks!