Step one: Talk to a lawyer and an accountant and have them document what you're entitled to based on the books and existing agreements. (You don't have to use t

Step one: Talk to a lawyer and an accountant and have them document what you're entitled to based on the books and existing agreements. (You don't have to use this, but you want to have it on hand if things get nasty.) Step Two: Decide what you're willing to live with based on what you learned in step one and have the lawyer draw up or validate an agreement based on those. Step Three: Have a talk with the other principles with the "What you're willing to agree to" document and the "What you're entitled to" document ready on hand. Decide which way is the one you want to offer them and be ready to pull the other if things go badly. Negotiate it out and keep everything in writing. Past that, pretty much everything is relationship/internal political issues that need to be resolved. But, make sure you talk to an accountant and/or a lawyer before putting anything on paper or signing anything.