A codicil is a legal document that amends or modifies an existing last will and testament. It allows you to make changes or updates without completely rewriting your will.  Here are 12 steps to guide you on how to write a codicil:

1. Review your current will: Before making any changes, thoroughly read and review your current will to clearly understand its provisions and identify what needs updating.

2. Consult an attorney: Although it is possible to write a codicil without legal assistance, consulting an attorney ensures that the document complies with the laws of your jurisdiction and reduces the risk of potential legal issues.

3. Identify the changes: List all changes you wish to make, whether these are updates in beneficiaries, asset allocations, or corrections of errors in the original will.

4. Number the paragraphs: Number each paragraph in your codicil consecutively to make it clear and easy to read.

5. Reference your original will: In the opening paragraph, clearly reference your original will by stating its execution date and any previous amendments (if applicable).

6. Specify the modifications: Clearly specify each modification by referring to the exact section or clause in the original will where the change is being made.

7. Be concise: Keep each modification short and focused, using plain language for clarity.

8. Revoke conflicting provisions: If your codicil makes changes that directly conflict with provisions in the original will, clearly state that those provisions are revoked.

9. Witness requirements: Typically, a codicil must be signed by two witnesses who meet eligibility requirements as outlined by your jurisdiction’s laws. Ensure both witnesses are not beneficiaries or have any vested interest in your estate.

10. Sign and date the document: Ideally, sign the codicil in front of a notary public (if required) and follow any additional execution requirements of your jurisdiction. Ensure the will and codicil share the same signature style to avoid potential challenges.

11. Keep the codicil with your original will: Store the original signed codicil together with your will in a safe place, and let your executor(s) know its location.

12. Regularly review and update: Life is unpredictable, and circumstances change. Review your will and codicil periodically to ensure it accurately reflects your current wishes.

In conclusion, writing a codicil ensures that your last will and testament remains updated and relevant to your ever-changing life. Follow these 12 steps to craft a clear, concise, and legally compliant codicil that embodies your final wishes.