My question involves employment and labor law for the state of: Texas

Hi there,
My boyfriend started a business and brought in three partners (B, C, & D). B & C are trying to eliminate D and my boyfriend, "A", would like to eliminate B & C. As you can see it doesn't make for vert smooth business decisions. Just recently my boyfriend has decided he would rather liquidate his shares and start another company than put up with the drama. However, there is a non compete clause in their contract.

The good news: the contract states that a Shareholder must sign off in order for the other Shareholder to be able to compete. Shareholder is defined for them as any one of the four Shareholders.

The question: Is it that easy? Or does my boyfriend have to declare his intent to sell his shares prior? (The contract gives clear information on how to procede after the declaration.) What if my boyfriend wants to take partner D with him? Can they sign each others non compete waivers? Can the waivers simply be two seperate notarized documents drawn by them and signed by the them and notarized a third party?