Your corporate governance docs should already have the mechanics in place for how this could work. Ask whomever is your attorney/accountant, and be ready to get

Your corporate governance docs should already have the mechanics in place for how this could work. Ask whomever is your attorney/accountant, and be ready to get one of your own. That being said, try not to accept equity. They can easily dilute that down to nothing in future deals. Ask them to buy out your stake, negotiate as appropriate to agree on a number, walk away with cash, call it a success story, and move on to whatever is next.