To remove an LLC member in California, you need a legal document known as an amended operating agreement reflecting the member's departure. From my legal experience, the first thing to do is ensure you have all the required information and legal documentation.
Explain the reasons for the withdrawal, giving as much detail as possible and being honest as to what led to the decision. As per the terms of the agreement, I will fulfill all obligations until the date of withdrawal and will do everything in my power to ensure a smooth transition.
When 1 of 2 members leave, the LLC loses it's partnership status and become a disregarded entity, unless it elected to be taxed as a corporation. You should read the original organization papers and operating agreement for the LLC. It should have spelled out what happens if one member wants out.
Make it official. Check your state Secretary of State's website for the form to file indicating that you are dissolving your LLC. Complete the form and follow the instructions for filing it with the state. This will formally close down the name of your LLC.
Provide written notification to the LLC of your intent to remove yourself. Receive what interest in the company you are due. (The other members are required to buy you out in line with the Articles of Organization and your share of ownership in the business.)
A member may withdraw, resign, or retire at any time by simply giving the other members written notice.