Shareholder agreement

Hey all,

In april last year i brought into a business with a partner and in July we sold a portion of our shares to a third party to assist buying out the original owner.

During the period in between Myself and my business partner created a new shareholder agreement to show the newly created shares and values. Due the drama of the old owner and slow payment from the new partner we have never updated the shareholder agreement. Sadly this has put us in a predicament as the new owner.. is useless and has cost us from the get go.

We have agreed to make his role in the company redundant, as it was just pure overhead and he agrees to this. Problem is as we dont have an updated shareholder agreement, and he knows it, we feel like we are stuck with our options.

My question is, the shareholder agreement in place states under the section of ASSIGNMENT:
"This Agreement is binding on, and continues for the benefit of, the parties and their respective successors and permitted assignees or transfees."

Does this mean, although the shareholder agreement hasnt been updated, its still the binding? and the clauses are valid?

My main clause i want in this agreement, is the buyout clauses and disagreement etc.

Thanks in advance.